From a Churchill to a corona to a grande size, the Montecristo White Series from Altadis U.S.A
but it was missing something—a double-tapered figurado
and the new Montecristo White Series Diadema will be heading to retailers on April 11
coinciding with this year’s PCA trade show
offers the Diadema in two packaging options: 10-count or 20-count boxes
it’s slated to retail for $22.50 per cigar
The company will be taking orders for the Diadema on the convention floor at the PCA trade show and will ship the cigars immediately after
The White Series was introduced in 2003 at the same trade show
back when it was called the Retail Tobacco Dealers of America trade show
While the Montecristo White Series leans light in terms of body
slightly spicier alternative to the Montecristo Classic Series
For a rating on the new Montecristo White Series Diadema, see a future issue of Cigar Insider
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At next month’s 2025 PCA Convention & Trade Show
will add a new vitola to its popular Montecristo White line
The company—which sells the non-Cuban Montecristo and Romeo y Julieta brands in the U.S.—will introduce the Montecristo White Diadema
the Montecristo White uses an Ecuadorian Connecticut-seed wrapper over a Nicaraguan binder and fillers from the Dominican Republic and Nicaragua
It will have an MSRP of $22.50 and will be offered in both 10- and 20-count boxes
“We are very pleased to introduce the Montecristo White Series Diadema as a new size offering,” said Marina Tuntes
“This release allows us to further showcase the range of Montecristo
a brand that continues to set the standard for consistency
quality and craftsmanship in the premium cigar world
We believe that the Montecristo White Series Diadema will become a standout addition for collectors who enjoy Montecristo.”
PCA 2025 takes place April 12-14 in New Orleans
intends to ship the cigars immediately after the trade show
Update — Altadis U.S.A. has sent over the press release. This story has been updated. Cigar Aficionado first reported the news
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The sea urchin Diadema africanum is a macro-herbivore found in the rocky reef systems of the West African region and Macaronesian archipelagos
high densities of this species have generated marine barrens in certain areas at the Canary Islands
the species has suffered mass mortality events that continue to the present day
we used 9,109 Single Nucleotide Polymorphisms (SNPs) and a fragment of a mitochondrial gene to evaluate the species’ population structure
effects of mass mortalities on its diversity
and potential local adaptation across the Canary Islands and Cabo Verde
Our research provides compelling evidence of low genomic diversity and homogeneity across the studied area for neutral markers
along with recent demographic fluctuations
The high connectivity among distant areas likely allows a rapid recovering of the populations from local mortality events
we also observed genomic sub-structure from 405 SNPs identified as candidate loci under selection for seawater temperature
The lack of divergence among distant sites and the low diversity found can be attributed to the species’ divergence from a small ancestral genomic pool
followed by a contemporary demographic expansion
africanum across its distribution range no previous population genetic studies have been performed to date
the effect of mass mortality events on intraspecific genetic diversity is still unknown
we here conduct a genome-wide analysis in D
africanum with the general aim of evaluating the genomic structure and diversity of its populations
and the potential patterns of substructure due to local adaptation
The specific objectives of this study were: (a) to explore the genomic structure and connectivity patterns of D
africanum across the Canary Islands and Cabo Verde; (b) to identify whether demographic fluctuations had an impact on the current levels of genomic diversity in the species
and (c) to identify potential patterns of local adaptation due to changes in the environmental variables along the Canary Islands
africanum holds low levels of divergence across the studied area due to its large dispersal capability but potential local adaptation
We also hypothesised that recent mass mortality events have reduced the genetic diversity of the affected populations
This information may help to predict the potential future vulnerability of the species in the Canary Islands and to predict future distribution shifts and abundance changes
Sampling sites of Diadema africanum for the COI analyses (black dots) and the SNPs analyses (red dots)
The pie charts represent the frequency of COI haplotypes in which each colour partitions correspond to a different haplotype
except for the white colour that represents private haplotypes
The maps were created using QGIS v.3.16.16 and edited in Adobe Illustrator
Over the entire dataset (Table 1)
the measures of haplotype and nucleotide diversity were relatively consistent across all sites within Cabo Verde and the Canary Islands
Considering the haplotype richness (Hk) and diversity (Hd) in the Canary Islands
the site of TC2 in Tenerife retained the highest values (Hk = 3.288
while the lowest values were found in the site of LC5 in the easternmost region of the Canary Islands (Hk = 0.890
haplotype richness ranged between 0.750 and 1 in Cabo Verde
ranging from 0.00038 ± 0.00019 in LC5 (Lanzarote) to 0.00149 ± 0.00034 in PC2 (La Palma)
The haplotype richness was low for almost all the sampled populations ranging from 0.890 for the LC5 site to 3.288 for the TC2 site in Tenerife
comparing both haplotype and nucleotide diversity between regions
the results showed no significant differences in diversity between them (s = 0.6546; p-value > 0.05)
the Canary Islands showed the highest diversity of haplotypes
Haplotype network from the COI dataset
and colour partitions indicate the sampling sites where it was sampled
The size of each circle is proportional to the haplotype frequency
Connecting lines among haplotypes represents a mutational step
and asterisks illustrate the non-synonymous substitution
Only the most common haplotypes are presented by their numbers (H1
This image was created using Popart v.1.7 and edited in Adobe Illustrator
was estimated between 28,800 and 45,500 years ago
The total dataset of D. africanum from ddRADseq loci included 9,109 SNPs from 179 individuals, from thirteen sampling sites in the Canary Islands (five from El Hierro, four from Tenerife, and four from Lanzarote) (see Fig. 1 and Table 2)
after removing 4 SNPs that were not in Hardy–Weinberg equilibrium in all populations
These sampling scheme included five sites affected by the last 2018 mass mortality event and eight sampling sites not affected by it
The total number of reads obtained was 1,269,736,321
with an average coverage of 7,093,499 (ranging from 727,179 to 43,584,550) reads per sample and 19.13% of missing data in the whole dataset
excluding all SNPs under potential selection
and the candidate SNPs under selection for temperature were 405 SNPs
identified using the Redundancy analyses (RDA) (see the Methods section for more details about how these datasets were created)
while no SNPs under selection were identified with BayeScan
with non-significant p-values (p-value > 0.05) after the FDR correction
Allele richness (AR) per locus and sampling site were very similar between them ranging from 1.495 in Td2 to 1.535 in Hd4
The populations affected and unaffected by the 2018 mass mortality event did not show significant differences in diversity for either allelic richness or observed heterozygosity (p-value > 0.05)
STRUCTURE barplots from the neutral SNPs (b)
The barplots are represented with the most probable number of genetic clusters (K = 3 and 2 for (b) and (c)
*The asterisk indicates the sites affected by the 2018 mass mortality event
This map was created in QGIS v.3.16.16 and edited with Adobe Illustrator
The Stairway Plot 2 results (Fig. 5) revealed the existence of a demographic expansion more than 100,000 years ago, reaching the population size a plateau approximately for ~ 90,000 years. According to the data, approximately 10,000–12,000 years ago, the effective population size of D. africanum has drastically decreased till today.
Demographic history of Diadema africanum inferred by Stairway Plot 2
The red line represents the effective population size (Ne) estimated over time
and the grey lines the 75% and 95% intervals of confidence
Axes represent time (x) and effective population size (y)
Our study undertakes sampling throughout a large part of the species’ distribution range
including populations that have undergone recent mass mortality events
Using 9,109 SNPs and a fragment of the mitochondrial COI gene
divergence patterns and historical demographic changes in this species
Considering the lack of an accurate molecular clock in Diadema for nuclear DNA
demographic results should be taken with caution and only considered as a broad approximation
but what they clearly reflect is the decline of D
suggesting that successful marine invertebrate species displaying low levels of diversity are more common than initially expected
our study demonstrates potential local adaptation to temperature
despite the existence of high levels of connectivity
This finding reinforces the idea that local adaptation can happen under high levels of gene flow by differential selective pressures across the genome
The local adaptation patterns can turn some populations
The existence of this genomic mosaic would claim the need of applying specific management strategies according to the characteristics of each geographical area
further identification of the involved genes in this adaptation would be needed to delve deeper into the biological
and/or physiological impacts of these genomic particularities
We should also keep in mind that only a small representation of the whole genome of D
other genome regions related to adaptation to environmental variables could be relevant to understand the genomic architecture of this species
we cannot anticipate how adaptation to local conditions of temperature could limit the recovery decimated populations
an interesting question that should be addressed in further studies
No endangered or protected species were involved in this study
Authors possessed the required permits to collect echinoderm samples for research
according to the number of comparisons between sampling sites
could not be further used for ddRADseq library construction due to their low quality of the nuclear DNA
africanum were collected from 13 sampling sites in the Canary Islands in 2021
Due to the low resolution of the COI for population genetics in this species (see the Results sections)
no sequencing of the COI was performed for the newly recollected samples
a small portion of the muscular tissue from Aristotle’s lantern was preserved in absolute ethanol at -20ºC
The module process_radtags was used to demultiplex and trim raw reads to remove low-quality and unidentifiable reads
The ustacks program was used to assemble the matching reads per individual and call SNPs at each locus
with a maximum distance allowed of 4 (-M) and a minimum of 3 matching reads to create a stack (-m)
The cstacks program was used to build a catalogue of consensus loci with 4 mismatches allowed between sample loci (-n)
Putative loci were searched against the catalogue using sstacks program and paired-end reads were associated with each single-end locus
The module populations was conducted retaining SNPs present in at least 75% of the individuals
SNPs that presented either significantly greater observed than expected heterozygosity (Hardy Weinberg Equilibrium-HWE
which can be interpreted as a sign of sequencing errors
or significant linkage disequilibrium (p-value < 0.01) in all sampling sites
This approach allows us to detect potential SNPs under selection to unknown variables (with BayeScan)
and specifically under selection to temperature (with RDA)
Using the information of potential SNPs under selection from both methods
we created two datasets: a dataset of SNPs excluding all candidate SNPs under selection
considered as a neutral dataset (neutral SNPs)
and a dataset including candidate SNPs under selection to temperature
most analyses explained below were computed for both datasets separately to highlight differences in structure between datasets as a sign of local adaptation
The FIS statistic was calculated in Arlequin
with 10,000 permutations to obtain their associated p-values
The relation between the population size and the number of alleles per sampling site was plotted with the package “ggplot2” in RStudio to check if the population size of our sampling was enough to represent the genomic diversity within the sites (data not shown)
We used the neutral SNPs dataset considering that mass mortality events equally influence the whole genome of the species
We performed the analyses applying separately the three mutation rates
we finally show in this study the ones associated with the 9.4 × 10−9
Each estimation was generated using 200 bootstrapped folded SFS
The COI haplotypes are available on NCBI GeneBank (accession numbers: OP494354-OP494596) and Illumina raw reads on the SRA database (BioProject ID PRJNA1065271; Biosamples SAMN39456622-SAMN39456864)
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and the project “DIVERGEN- Ayudas Fundación BBVA a Proyectos Investigación Científica 2021”
This paper is a contribution of the Consolidated Research Team: 2021 SGR 01271 Marine Biodiversity and Evolution (MBE)
Spanish Government projects: ADAPTIVE- PGC2018-100735-B-I00 (MCIU/AEI/FEDER. UE), ENVIOME (PID2021-128094NB-I00/MCIN/AEI/https://doi.org/10.13039/501100011033/ and FEDER una manera de hacer Europa)
Laia Pérez-Sorribes & Rocio Pérez-Portela
Instituto de Engenharias e Ciências do Mar
Centro de Investigação em Biodiversidade e Recursos Genéticos
Institut de Recerca de la Biodiversitat (IRBio)
and R.P-P wrote the first draft of the manuscript
and all the other authors improved this first draft
All authors agreed with the final version of this manuscript
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This study identifies the gut microbiota changes associated with the D. antillarum during this mortality event. It contrasts them with the bacterial composition of gut samples from healthy individuals collected in 2019 by using 16S rRNA sequencing analyses.
Notably, the die-off group’s core microbiome resembled bacteria commonly found in the human skin and gut, suggesting potential anthropogenic contamination and wastewater pollution as contributing factors to the 2022 dysbiosis. The animals collected in 2022, especially those with signs of disease, lacked keystone taxa normally found in Diadema including Photobacterium and Propionigenium.
Volume 15 - 2024 | https://doi.org/10.3389/fmicb.2024.1409729
Caribbean coral reefs have lost many vital marine species due to diseases
The well-documented mass mortality event of the long-spined black sea urchin Diadema antillarum in the early 1980s stands out among these collapses
antillarum changing the reefscape from coral to algal-dominated
antillarum populations have yet to recover
antillarum was reported along the Caribbean
Methods: This study identifies the gut microbiota changes associated with the D
It contrasts them with the bacterial composition of gut samples from healthy individuals collected in 2019 by using 16S rRNA sequencing analyses
the die-off group’s core microbiome resembled bacteria commonly found in the human skin and gut
suggesting potential anthropogenic contamination and wastewater pollution as contributing factors to the 2022 dysbiosis
lacked keystone taxa normally found in Diadema including Photobacterium and Propionigenium
Discussion: The association between human microbes and disease stages in the long-spined urchin D
especially in relation to anthropogenic contamination
highlights a complex interplay between environmental stressors and marine health
While these microbes might not be the direct cause of death in this species of sea urchins
their presence and proliferation can indicate underlying issues
that ultimately compromise the health of these marine organisms
The findings revealed a distinct partitioning of microbiota based on the specific feeding niches of each sea urchin species
with sea urchins from the reef environments showing a prevalence of sulfate-reducing bacteria
whereas those inhabiting seagrass habitats exhibited a dominance of Planctomycetes and Cyanobacteria
These parasitic (ciliate) diseases affecting these sea urchins can have significant ecological impacts and include changes in the physiological balance of the animal’s microbiota
This study leverages samples collected before (i.e.
2019) and during the initial stage of the 2022 die-off emergency to investigate its impact on the gut prokaryotic communities of D
We hypothesize that there would be changes in the microbiota among the animals collected previous to and during the 2022 die-off event
Understanding the relationship between microbial communities and sea urchin health is crucial for conservation efforts
antillarum individuals (n = 23) were collected in their reef habitats in 2019 and early 2022
antillarum individuals were sighted at the time of the surveys
Surveyed sites in 2019 and 2022 for the analysis along the northern coasts of Puerto Rico and Culebra Islands
The 2019 locations represented in green color circles are Cerro Gordo (CGD)
and Isla de Cabras en Cataño (CAT)
The 2022 locations represented in orange triangles are Escambron (ESC)
We monitored the experimentally induced sedation until all specimens detached from the beaker walls
Individuals were carefully transferred to a metal tray and exposed to an ultra-low temperature of −80°C for 10 min (thermal shock) before dissection
Fecal pellets were carefully collected from the animal’s guts
Sample read pre-processing was done using QIITA (version 2022.09). The 16S rRNA genes were trimmed to 250 bp and classified using the SILVA database’s closed reference approach (Quast et al., 2013)
and singletons (n < 5) were removed from downstream analyses
Finally, the compositional heatmap (considering the site of collection) and heat tree compare overall taxa significantly changing in pre-die-off and die-off groups. This analysis was done with the MicrobiomeAnalyst online tool (Dhariwal et al., 2017) using standard parameters
considering only reads present in at least 20% of the samples (20% core taxa)
and total sum scaling without transformation
Bacterial taxa associated with the health status per year, per collection site, were identified using Multivariate Analysis by Linear Models (MaAsLin2) (Mallick et al., 2021)
MaAsLin is a comprehensive R package for determining the multivariable association between metadata and microbial features
After pattern matching to allow flexible capitalization of the correction argument
“fdr” resolves to “BH” in p.adjust and gives a list of p-values and adjusted q-values which are plotted for <0.05 in a heatmap
The MaAsLin2 model included the health status (healthy vs
diseased) correcting for the collection years (2019 vs
we compared the diseased animals (collected in 2022) with those that resembled healthy (collected in 2019)
We selected metabolic functions with only positive values and those with a standard deviation higher than 0.01 to compare (1) the health status considering the year (2019_healthy
and 2022_diseased) and (2) the different collection sites per year (“2019_CAT,” “2019_CGD,” “2019_LUQ,” “2022_CUL,” and “2022_ESC”)
the lack of the rigorous planned nature of the study
environmental parameters were not measured
the similarity among animal microbiota across sites
with only ESC being in a highly populated area among the 2022 samples
suggests minimal environmental variation between sites
This leads us to believe that any environmental differences that may have existed had a negligible impact on the animal’s microbial communities
Taxonomic barplots at the phylum (D) and genus levels (E)
panels are dividing the three groups of healthy and diseased animals collected in 2019 and 2022
The reads were rarefied at 923 for this analysis
The taxonomic composition also differed between the 2019_healthy group and the 2022 groups (whether visually healthy or diseased and independently of the site of collection) (Figures 2D,E)
whether they were visually healthy or diseased
This contrast in bacterial dominance may suggest that the diseased individuals were at different stages of the disease
finding the same human-derived bacteria augmented in the die-off period (shown in blue as reduced in pre-die-off samples)
Heatmaps show genus-level changes in the microbiota
(A) Overall differences between sea urchin’s health year and collection sites
(B) Heatmap resulting from the bacterial Multivariate Analysis by Linear Models (MaAsLin) comparing healthy and diseased animals in 2022 using as reference the healthy animal microbiota from 2019 samples
Red (+) indicates a positive association while blue (−) a negative one
Boxplots showing the significant differences in bacterial functional activity between the three groups of healthy and diseased animals collected in 2019 and 2022
using Functional Activity of Prokaryote taxa (FAPROTAX) database (A–G)
The functions shown are those that showed a standard deviation higher than 0.01 when comparing the relative abundance of functional
In addition, there was a loss of characteristic taxa in healthy echinoderms, that is, Prolixibacter, Propionigenium, and Photobacterium (Yao et al., 2019)
antillarum microbial profiles could be explained by the disease stage
those diseased individuals with gut microbiota profiles closer to healthy individuals (i.e.
pre-die-off individuals) might be at an earlier disease stage than those individuals with microbiota profiles far apart from healthy individuals
The absence or the reduction in the abundance of keystone bacterial groups in diseased individuals was more a direct consequence of the pathogenic scuticociliate Philaster apodigitiformis than a cause of a pre-disease susceptibility immunological condition
To conclude, using new molecular technologies such as 16S rRNA sequencing has significantly enhanced ecological studies in microbiology and our comprehension of ecology, physiology, and interactions within marine ecosystems (Rodríguez-Barreras, 2024)
High-throughput metagenomic studies have significantly broadened our understanding of diseases in marine animals
revealing the intricate microbial communities associated with health and disease states in these organisms
as well as not including another multi-kingdom such as eukaryotes
reveal a dramatic community shift in bacterial diversity and composition in the gut microbiome of D
antillarum during the 2022 die-off event in Puerto Rico and perhaps in other jurisdictions along the Caribbean basin
The core microbiome changed between the two groups
indicating a significant restructuring of the sea urchin gut prokaryote community
The described microbiota dysbiosis might be linked with the presence of the pathogenic scuticociliate species Philaster apodigitiformis and
to human-derived activities such as sewage water pollution
these findings provide valuable insights into the complex interactions between sea urchins
and environmental factors during disease events
highlighting the need for further research into the ecological implications of these microbial changes
The datasets generated for this study can be found in the European Nucleotide Archive Project (ENA) with access numbers EBI: ERP155238 (2022 animals) and ERP123720 (2019 animals)
The animal study was approved by University of Puerto Rico Medical Sciences Campus IACUC protocol (IACUC #: A5301118)
The study was conducted in accordance with the local legislation and institutional requirements
The author(s) declare that financial support was received for the research
This study received funding support from the NSF-OCE Biological Oceanography award #2243580 (CT-H
and the BiRC Core of the Puerto Rico IDeA Networks of Biomedical Research Excellence
Advancing Competitive Biomedical Research in Puerto Rico
5P20GM103475-20 (FGV) and NIH/NIMHD RCMI U54MD007600
The authors would like to thank the Sociedad Ambiente Marino for their invaluable logistical support
The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest
All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations
Any product that may be evaluated in this article
or claim that may be made by its manufacturer
is not guaranteed or endorsed by the publisher
The Supplementary material for this article can be found online at: https://www.frontiersin.org/articles/10.3389/fmicb.2024.1409729/full#supplementary-material
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Received: 02 April 2024; Accepted: 27 June 2024; Published: 29 July 2024
Copyright © 2024 Ruiz-Barrionuevo, Kardas, Rodríguez-Barreras, Quiñones-Otero, Ruiz-Diaz, Toledo-Hernández and Godoy-Vitorino. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY)
distribution or reproduction in other forums is permitted
provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited
in accordance with accepted academic practice
distribution or reproduction is permitted which does not comply with these terms
*Correspondence: Filipa Godoy-Vitorino, ZmlsaXBhLmdvZG95QHVwci5lZHU=
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Volume 3 - 2016 | https://doi.org/10.3389/fmars.2016.00063
We carried out detailed surveys of a recovering population of D
antillarum in Curacao to document an ongoing influence of habitat type on population density
and to explore what ecosystem characteristics might drive observed recovery patterns
and predatory fish biomass in sites with and without structural complexity on reefs in sheltered lagoon and backreef locations
antillarum densities were greatest in sheltered lagoon and backreef locations
densities were significantly lower than those reported prior to the mass mortality event
Larval settlement rates were greater in sheltered lagoon and backreef locations but did not fully account for observed patterns in urchin density
Sheltered lagoon and backreef habitats had more turf algae and fewer herbivorous fish than forereef habitats
Predator abundance was generally low and did not differ significantly among habitat types
antillarum recovery in Curacao are consistent with dynamics expected in the presence of density-dependent habitat selection
More algal resources and fewer herbivorous fish provide a mechanism for increased fitness and habitat suitability in sheltered
will only be re-colonized once the carrying capacity of more favorable habitats is exceeded
We propose a number of testable predictions to explore this theory further
and advocate for including sheltered lagoon and backreef habitats in D
antillarum population surveys to monitor recovery
as well as protecting populations found in these habitats where necessary
We predict that when current populations return to pre-mortality densities
range expansion may allow for a return of D
antillarum population recovery is of great interest to coral reef managers and is widely considered to be an important and positive mechanism to promote reef recovery
Detailed surveys of the established D. antillarum population of Curacao were carried out between May 25th and August 27th 2010. Table 1 summarizes the hypotheses tested and the data collected
All activities carried out within the scope of the study were non-invasive
and did not require specific permission or permits
Table S1 in the online supplementary material provides all of the data presented and discussed in this paper
all surveys were conducted at depths of 6 m or less
Breakwater habitats were also included as structurally complex
transects 25 m long by 4 m wide were established and marked (n = 3)
For each treatment group (sheltered low-relief
Map of Curacao showing the 20 survey locations on the leeward shore
*Depicts locations where larval settlement plates were deployed
Plates were checked at approximately monthly intervals over a 3-month period
antillarum discovered were counted and removed
An average rate of settlement based on all three collections was calculated and taken forward for further analyses
Percent cover of turf algae was estimated based on 100 random points overlaying a total area of 864 cm2 from two pictures
one on either side of each settlement plate
This measure reflects net turf algal abundance and takes into account the confounding influence of grazing by herbivorous fish
but not by resident urchins that could not access plates in mid-water
Percent cover of macroalgae was estimated in 25 randomly distributed 0.25 m2 quadrats along each transect during August 2010
Quadrats were divided into 25 squares (each representing 4% of the total cover) and the number of squares dominated by fleshy macroalgae was recorded
Results were scaled up to represent percent cover within a transect and percentages were then averaged to give a mean percent cover per site
error bars represent ± 1 standard error)
Summary of statistical analyses from the study of D
antillarum populations and associated population dynamic drivers in Curacao in 2010
and are absent for pre-mortality data in sheltered locations due to a lack of available data
D. antillarum larval settlement was variable in space, with significantly higher rates observed in sheltered habitats (0.86 ± 0.28) vs. forereef (0.24 ± 0.12) locations (p = 0.05, df = 14, Table 2; Figure 3)
We did not test for a response in larval settlement to habitat structural complexity because larvae settling on uniform settlement plates will not be influenced by substrate complexity
Our results suggest that sheltered habitats may have higher larval retention or increased larval production
there was no significant correlation between larval settlement and population density
which implies that post-settlement processes
antillarum larval settlement rates in sheltered and fore-reef habitats in Curacao
Error bars represent 95% confidence intervals
error bars in figures represent 95% confidence intervals)
The ecological factors hypothesized to influence D
The spatial distribution of D. antillarum populations in Curacao in 2010, when combined with survey data from previous years (Debrot and Nagelkerken, 2006; Vermeij et al., 2010), support the conclusion that recovery is largely restricted to sheltered lagoon and backreef habitats. The same pattern has also been documented elsewhere (Miller R. J. et al., 2003; Steiner and Williams, 2006)
we set out not only to document this continued trend in Curacao
but also to explore the processes likely to drive the pattern and shed light on why D
antillarum continue to be scarce on the forereef where they were once prevalent
Our data allowed us to decouple the effects of habitat type and habitat complexity
We then examined differences in larval settlement rates
and ecological factors influencing post-settlement recruitment and survival among distinct habitat types
antillarum larval settlement rates and population densities were both greater on average in sheltered versus forereef habitats in Curacao
tests for a direct correlation between larval settlement rates and population density were non-significant
It was not possible within the realm of this study to ascertain whether sheltered habitats have higher larval settlement rates due to larval retention or higher production
or whether established populations provide increased settlement cues
Further studies of larval supply and settlement dynamics are important for our understanding of D
to what extent larval supply and larval retention drive population abundances
the non-correlation between larval settlement and established populations implies that larval supply is not limiting
and post-settlement processes are also important in determining observed spatial distributions of D
Whether we consider algal turf growth and herbivorous fish abundance independently or in combination
we find that increased resource availability and reduced resource competition are each potential mechanisms for increased suitability of sheltered habitats for D
Further work is needed to thoroughly test the effect of macroalgae on D
macroalgal cover does not have a negative impact on D
This could be a real concern for widespread D
antillarum recovery in light of our results
It raises the question of whether Caribbean reefs have changed so much in the past decades that their habitat suitability to D
We therefore conclude that there is both pattern and process evidence for a role of density-dependent habitat selection in the recovery dynamics of D
A number of testable predictions would lend additional support to this hypothesis and improve our understanding of the recovery dynamics of D
forereef locations under current conditions; (ii) Resources for D
antillarum are limited in Curacao (and perhaps elsewhere) in forereef habitats; and (iii) D
antillarum larvae can detect and respond to resource availability and preferentially settle in favorable habitats
With respect to management and promotion of D
we advocate measures to monitor and protect locally dense wild populations
and other “undesirable” locations where their grazing function is not perceived to be important
We recommend including more of these habitat types in population surveys and protecting populations found in them where necessary
given the observed ubiquitous benefit of complex over non-complex substrates for D
and/or restoration of structural complexity in shallow sheltered and forereef habitats is likely to be essential for widespread population recovery
This work was funded by a PhD scholarship to AR from the Natural Environment Research Council (NERC)
We thank the staff of the CARMABI research station for their help and advice and many thanks to Ben Roberts and Alexandra Prebble for fieldwork excellence
The Supplementary Material for this article can be found online at: http://journal.frontiersin.org/article/10.3389/fmars.2016.00063
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Citation: Rogers A and Lorenzen K (2016) Does Slow and Variable Recovery of Diadema antillarum on Caribbean Fore-Reefs Reflect Density-Dependent Habitat Selection
Received: 28 August 2015; Accepted: 18 April 2016; Published: 02 May 2016
Copyright © 2016 Rogers and Lorenzen. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY)
provided the original author(s) or licensor are credited and that the original publication in this journal is cited
*Correspondence: Alice Rogers, YS5yb2dlcnMyQHVxLmVkdS5hdQ==
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Norwegian (NCL) Cruises to the Mediterranean
Royal Caribbean Cruises to the Mediterranean
Volume 10 - 2023 | https://doi.org/10.3389/fmars.2023.1152584
The Eastern Mediterranean Sea is an exceptional habitat
Its relative isolation and distinct characteristics create a unique ecosystem recognized as a marine biodiversity hot spot
where one-fifth of the species are endemic
native Mediterranean biodiversity is under increasing threat
mainly due to massive alien species invasions of Indo-Pacific origin
more than 800 non-indigenous species have been reported in the Eastern Mediterranean Sea
justifying its reputation as one of the most severely affected habitats in the world in terms of marine biological invasions
Here we summarized the Mediterranean invasion dynamics of the long-spined echinoid Diadema setosum (Leske
one of the most ubiquitous Indo-Pacific sea urchin species
We show an alarming exponential population growth of D
setosum throughout the Eastern Mediterranean since 2018
following more than a decade of ‘invasion lag’ since its first detection in 2006
Molecular analyses illustrate the presence of a single genetic D
setosum clade in the Mediterranean Sea – corresponding to the Arabian Peninsula clade of this species
reinforcing the notion of a Red Sea origin
Our data support the current working hypothesis that the initial introduction of D
setosum occurred in the Northern Levantine Basin from which it gradually expanded in both north-west and south-east trajectories – in contrast to a stepping-stone hypothesis of gradual advancement from the opening of the Suez Canal
setosum along the Israeli Mediterranean coastline reveals a well-established population of broad size distributions
from juveniles to adult individuals of remarkably large size
we provide evidence of the reproductive capacity of D
Due to the magnitude of Diadema’s ecological footprint
it poses a severe threat to the entire Eastern Mediterranean Sea
including the Levantine Basin and South Aegean Sea
calling for rapid and coordinated action at both national and regional scales
Figure 1 Schematic invasion curve specifying Diadema setosum invasion timeline in the Mediterranean Sea
Following transport and introduction to the new region
founder non-indigenous species (NIS) populations remain restricted in both population size and range
The invasion lag-phase occurs at the onset of NIS establishment and is characterized by restricted spatial distributions and low abundances
population size dramatically increases and includes individuals at varying life stages
population outbreaks may occur as NIS achieve exponential population-growth and range expansion
Vertical dow-facing arrows indicate the year of first D
setosum record for the respective countries
none has so far targeted populations from the Eastern Levantine Basin
The first record of D. setosum in the Mediterranean Sea in 2006, off the Kaş Peninsula, Turkey, (Yokes and Galil, 2006) was a milestone in the successful establishment of large aggregations currently occupying the entire Levantine Basin (Figure 2)
Figure 2 Map of the Eastern Mediterranean Sea. Red dots (transparent red symbols) represent sites of Diadema setosum observations compiled over nearly two decades – from the detection of the first individual in 2006 to the end of 2022. The map was created using QGIS v. 3.28.2 (QGIS Development Team, 2023)
demonstrating its range expansion and recent accelerated population growth reflecting clear signs of population outbreak
We combine a thorough literature review with extensive survey data and sampling complemented by citizen-science reports
to provide a comprehensive report on the progress of this invasion and depict its true scale
We use molecular data to identify the genetic makeup of the invaders and determine their origin
We show an alarming recent exponential increase in D
setosum abundance in the Eastern Mediterranean and provide evidence of effective reproductive capacity (i.e.
the ability of an individual to reproduce) in their new environment
Our results shed new light on both temporal and spatial dynamics of biological invasions in the Mediterranean Sea and facilitate better understanding of the life history
and reproductive biology of the ubiquitous D
Underwater surveys were conducted between 2016 and 2022 along the Greek, Turkish, Cypriot, and Israeli Mediterranean coastline, and published data were obtained from the literature and complimented by citizen reports (Table S1)
Data from a total of 670 reports comprising: 313 reports from scientific literature
237 underwater survey dives by trained biologists
covering a depth range of 0-50 m and spanning over 2,000 km of the Eastern Mediterranean Sea
Data were used to construct two datasets: (1) ‘number of individuals’ – the total number of Diadema setosum individuals encountered on a 45 min dive
and (2) ‘number of observations’ – each independent dive where Diadema setosum are observed was counted as one
regardless of the number of individuals encountered
counts were conducted by a single observer
and dives were regarded as independent reports if conducted at different sites or on different dates
Considering the potential biases originating from citizen science
strict criteria for evaluating these data were established
Reports missing the exact number of individuals encountered
and/or precise localities (coordinates) were omitted from downstream analyses
In reports where the number of individuals was ambiguous
values were determined following personal communication with the reporter or else omitted
the observations were omitted from the analysis
48 reports were omitted based on these criteria
To avoid instances of misidentification of D
such data were included only if accompanied by photographic evidence
allowing unambiguous identification prior to inclusion in our dataset
When possible, specimens were collected for morphological examinations as well as molecular and histological analyses. In total, 24 D. setosum specimens were collected along the Israeli Mediterranean (specimens are deposited at the Steinhardt Museum of Natural History collection, Tel Aviv University, Israel) (Table S2)
Twelve additional tissue samples of adult specimens were collected in Crete
and five tissue samples were collected from the native Red Sea population (Eilat
The latter providing test diameters of 160 randomly selected individuals
Table 1 List of primers used for the molecular analysis
the first 25% of trees were discarded as burn-in
and a 50% majority-rule consensus tree was calculated from the remaining trees
Posterior Probabilities (PP) were obtained from the 50% majority-rule consensus of the trees sampled during the stationary phase
setosum’s reproductive cycle: Stage I (spent): Gonads are largely devoid of contents showing ova-free lumen in females and spermatozoan-free lumen in males
A thin layer of nutritive phagocytes (NPs) is present along the ascinal walls in both sexes and may form a pale meshwork across the ascinus
Strongly basophilic previtellogenetic oocytes or primary spermatocytes
staining dark purple with Hematoxylin and eosin
Stage II (recovering): NPs proliferate from the gonad ascinal wall
gradually filling the lumen of both ovaries and testis
Limited groups of primary spermatocytes and clusters of previtellogenetic oocytes start appearing in the testicular and ovarian germinal epithelia
Stage III (growing): Both early and late vitellogenetic oocytes may be present along the ovarian wall
All stages of germ cells are evident in the male germinal epithelium and continuously increase in number as new spermatogonia develop basally while spermatocytes migrate to the testicular lumen
where they accumulate as mature spermatozoa
forming visible columns of darkly stained cells
NPs deplete and progressively occupy less space in both males and females
Stage IV (mature): By the end of this stage the NP layer in both ovaries and testes is largely exhausted
while oocytes at different maturation stages may still be evident in the germinal epithelium
The testicular lumen is densely packed with spermatozoa
Occasionally some ova and spermatozoa may be evident in the coelom
Due to multiple testing for the size frequency comparisons
p-value was corrected using the Bonferroni correction
To test for the differences in male-female ratios
Figure 3 Annual Diadema setosum number of observations and number of individuals in the Mediterranean Sea between 2006 and 2022
Color indicates the country from which the report originates
Column pairs (per year) represent number of observations (left) and number of individuals (right)
the majority of individuals were spotted around the coasts of Turkey (n=19,034) and Greece (n=4,853)
Similar to the Israeli Mediterranean population
very small (10–20 mm) and very large (80–90 mm) individuals were the least frequent (1% and 4%
SFD of the Israeli population seems to be more biased towards the smaller size groups (10–20 and 20–30 mm) than the Greek population
both Greek and Israeli populations showed a high proportion of juveniles compared to adults
setosum from its native RS range differed significantly from both Israeli (Kolmogorov-Smirnov; p=0.0211) and Greek (Kolmogorov-Smirnov; p<0.0001) Mediterranean populations
Specimens in the RS had distinctly smaller body size
the RS was the only locality where individuals smaller than 10 mm (7.5%) could be observed
The RS population was strongly skewed towards smaller individuals with most individuals ranging between 10 to 30 mm in diameter
The occurrence of individuals larger than 50 mm in the RS was negligible (1.3%)
Figure 4 Size-frequency distributions of Diadema setosum at three localities: a native population at the Gulf of Aqaba, Red Sea (Is-RS; n=547), measured between 2007 and 2008; Israeli Mediterranean population (Is-Med; n=24), measured between 2019 and 2021; and Greek population (Gre-Med; n=160), measured between 2019 and 2020 (modified from Vafidis et al., 2021)
As phylogenetic analyses generated congruent topologies
only ML trees are presented – showing both bootstrap support values and posterior probabilities for the respective nodes
Scale bar reflects number of changes per site
Whether the present Mediterranean population represent the descendants of a single invasion event prior to 2006
Molecular population genetics may help resolve this question once sufficient samples are obtained from across the Eastern Mediterranean
Given the conspicuous appearance and non-cryptic nature of D. setosum, early detection of this species in the Mediterranean was possible. Moreover, the hard substrate preference, and depth range preference of Diadema, reaching the shallow depths of the lower intertidal, makes it readily detectible at highly monitored sites along the Mediterranean coastline. Consequently, the first report of this species in 2006 (Yokes and Galil, 2006)
likely occurred shortly following the species arrival to the Mediterranean
offering a rare opportunity to study the dynamics of marine invasions
the exponential increase in number of observations in the following years
can only be attributed to the rapid proliferation of D
regional scale monitoring is needed to depict the fine scale dynamics of this invasion
setosum under the less favorable conditions of the northern Levant (in comparison to the Southeastern Levant)
support the assumption of gradual establishment starting in the north and gradually expanding southwards
the addition of a strong echinoid competitor to the largely vacant niche is likely to aid the expansion of D
and further restrict the recovery of native species
growing populations gradually increase the chances of successful fertilizations
leading to the formation of larger larval stocks
a higher number of juveniles will potentially be recruited
as these juveniles grow to sexual maturity
despite the close geographic proximity and favoring surface currents from the assumed point of introduction in Kaş
The elaborated network of regional shipping routes in the Eastern Mediterranean likely contributed to D
Figure 7 Map of main shipping routes in the Eastern Mediterranean Sea during 2021. Data obtained from https://www.marinetraffic.com/
Color gradient scale represents – routes/2.45km2/year
Estimates of the Israeli SFD are based on a limited dataset and clearly more data is needed to capture the true size structure of this population
the presence of individuals across the species size range
sustainable populations in the Mediterranean
demonstrating ongoing recruitment and survival of offspring – most likely originating from sexually reproducing local populations
the first specimen collected in Kaş in 2006 was 58 mm
Though the introduction of adults cannot be ruled out at this stage
ballast water transport of larvae is still the most likely means of transport
the presence of such large specimens indicates a minimum two-decade long presence of D
Further insights might be gained by comparing size frequency distributions between the native population in the RS, the more established Mediterranean population in the Aegean Sea and the proliferating southern Levant population in Israel. Indeed, the Greek population displayed size distributions similar to the Israeli Mediterranean population, showing elevated frequencies of young individuals in the size range of 10 to 30 mm (Figure 4)
The abundance of juveniles (compared to adults) at both Greek and Israeli populations
suggest high larval supply for these populations followed by high mortality rates post recruitment
While the drivers of these selective adult mortalities are currently unknown
elevated predation of the less cryptic adults may provide some explanations
the enhanced body size in Mediterranean populations may indicate the current lack of such selective forces in the Levant
The lower abundance of potential Diadema spp
supporting enhanced body size and longevity
which in turn increases the species reproductive potential and accelerate the species proliferation
Though the spatial scale of these events is
imposing an immediate threat to both local fauna as well as native RS D
and call for close monitoring of these events
setosum is now well established in the Mediterranean Sea
The exponential growth phase currently reached in the Northern Levant marks the shift of D
setosum proliferation to population outbreak
While the full scope and outcomes of this successful invasion are still unclear
the potential risk for the already disrupted environment of the Eastern Mediterranean
and the emerging signs of pathogenic infections
are some of the major concerns associated with the current invasion
To preserve the unique ecosystem of the Eastern Mediterranean
Regional collaboration will be effective not only for the current D
but also aid in mitigation of upcoming invasions by NIS that are already making their way to the Mediterranean Sea
The datasets presented in this study can be found in online repositories. The names of the repository/repositories and accession number(s) can be found in the article/Supplementary Material
Analysis and interpretation of results: RZ
All authors reviewed the results and approved the final version of the manuscript
This research was supported by the Israel Science Foundation (ISF; grant number 2407/20) and Yad Hanadiv Foundation (grant number 10699) to OB
Field research in Turkey was partially supported by WWF-Turkey
This work was facilitated by the Mediterranean Diadema Response Network (MDRN) – an international collaboration of scientists and stakeholders from Cyprus
regional scale monitoring of the invasive D
Institutional support was provided by the Steinhardt Museum of Natural History
Nir Stern of the Israel Oceanographic and Limnological Research for facilitating this international collaboration
and Alex Geyzner for their contributions to data collection
Field work was supported by the Dive2gether and Mare Mundi Marine Field Station in Plakias
and Enalia Physis Environmental Research Centre and Deep Dive and ScubaCyprus Dive Centers (CJ
All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations
The Supplementary Material for this article can be found online at: https://www.frontiersin.org/articles/10.3389/fmars.2023.1152584/full#supplementary-material
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Received: 27 January 2023; Accepted: 15 May 2023;Published: 31 May 2023
Copyright © 2023 Zirler, Leck, Farkash, Holzknecht, Kroh, Gerovasileiou, Huseyinoglu, Jimenez, Resaikos, Yokeş and Bronstein. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY)
*Correspondence: Omri Bronstein, YnJvbnN0ZWluQHRhdWV4LnRhdS5hYy5pbA==
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Marine life can be susceptible to diseases just like people
and ecosystems that depend on them can also be impacted
we discuss the disease affecting sea urchin populations in the Caribbean
and NOAA’s role in helping to monitor this event
We’re joined by one of our experts from NOAA’s Coral Reef Conservation Program
who is the National Coral Reef Monitoring Program Coordinator
The Coral Program is a partnership between many NOAA offices that work on coral reef issues
The Monitoring Program is an integrated and focused monitoring effort with partners across the United States
HOST: Let’s talk about the long-spined sea urchin
Why are they considered an important organism and how are they being impacted by a disease that is affecting their populations in areas of the Caribbean
National Coral Reef Monitoring Program Coordinator
TOWLE: The long-spined sea urchin is one of the most important herbivores in Caribbean reef systems and an herbivore means it eats algae
it’s essentially a “cleaner” on the reef - by preventing algal overgrowth so that corals
which of course are the foundation of the reef habitat
scientists learned of an extensive long-spined sea urchin disease and die-offs in St
It appears that signs of the disease progress very rapidly and usually within one to two days of signs of sickness
And what we mean by signs of sickness are things like excess mucus on their spines
or they actually may lose their ability to attach to the reef
our scientists have noted that their spines may actually start to fall off and their tissue may sort of slough off
there have been even more mortality events in St
and more than 18 other Caribbean islands or territories
HOST: Have these events occurred in the past in the Caribbean with the long-spined sea urchin
Diadema antillarum previously experienced a region-wide massive die-off throughout the Caribbean in the 1980s
HOST: What were the causes behind the events that took place in the 1980s and was this species able to recover
Sampling at that time in the 1980s was inadequate to fully determine the cause of that disease event
but it appeared to be water-borne and scientists speculate it was transmissible via ocean surface currents
And so the fact that the 1980s outbreak only affected one species
it suggests also that a host-specific pathogen could have been involved
Very few Diadema populations have fully recovered even though it has been four decades
so many Caribbean reefs are in this algal-dominated state that I mentioned earlier without the urchins sort of playing their role as cleaners on the reef
The question of if they can recover is a really good one that’s really important right now
To understand that a little better we have to look back to the previous mass mortality event from the 80s that we just talked about
what we do know is that the 1980s die-off reduced populations by 90 percent in many areas in the Caribbean
which reduced the number of urchins that were able to reproduce and regrow the population naturally
But the good news is there were some survivors who were naturally hardy or stress tolerant
And so the hope really now is that because Diadema is a species that has a very wide geographical distribution across the Caribbean and they also have larvae
that can be carried by ocean currents before they settle on a reef
that they might have the ability to repopulate areas affected by the die-offs
HOST: That sounds like a huge impact to the urchin populations in the affected areas
It’s just that the recovery levels are still far below where we’d like them to be or where we need them to be
We don’t fully understand the factors that limited higher recovery from the 1980s die-off
but some of them could be related to the fact that adult densities might have been too low to repopulate the population
It could also have to do with the fact that the baby urchins didn’t have a high survival rate
or it could be that there was degraded coral reef habitat that wasn’t good for the baby urchins to settle on
It could also be a combination of all of those things
we hope that there will be some recovery similar to the aftermath of the 1980s die-off
But there is a lot of concern right now because populations have not fully recovered from the first event and now we seem to be in the midst of another population crash
HOST: And when you mentioned adult densities that were too low
do you mean just their numbers weren’t high to really support an increased population
Meaning that there weren’t enough adult urchins to repopulate and reproduce to make new populations
HOST: We previously mentioned how the sea urchin is an important herbivore
What would be the impacts to the local ecosystems if this organism’s population did continue to decline
TOWLE: Losing urchins on reefs is very detrimental to a coral reef ecosystem because it usually means massive algal overgrowth occurs
the algae takes over the spaces that coral would normally grow
and we refer to that as something called a phase shift
where essentially we would go from a coral-dominated reef to an algal-dominated reef
Other scientists also refer to that phenomenon as a “slippery slope to slime”
basically meaning that a reef will transition from what we might be able to picture as a beautiful
HOST: And is it correct to assume a slimy algae forest isn’t the best type of situation for the coral reef
So once a reef goes into this algal dominated phase shift
it’s really difficult to come back from that
and it can take a long time for a reef to recover
If all the spaces on the reef is taken up by algae
And then once you lose that complex structure of your coral reef
many of the animals that rely on coral reefs as their habitat will have nowhere to live
many fish species that live on coral reefs would lose their home
that can actually affect food supply for people that rely on fishing to feed their families
the structure of a coral reef habitat provides a very important protection from storm surge to the coast
So without coral reef structure to reduce wave action from storms on to the shoreline
the coast is going to face greater damages when we have severe storms like hurricanes for example
losing urchins can actually have a lot of very serious and very negative consequences even beyond the local coral reef itself
The National Coral Reef Monitoring Program is contributing to monitoring the health of the sea urchins along the entire Florida Reef Tract and Flower Garden Banks National Marine Sanctuary in summer 2022
This information will be shared with NOS partners and colleagues at the Atlantic and Gulf Rapid Reef Assessment
HOST: How is the National Coral Reef Monitoring Program working to understand the causes of the sea urchin die-offs
the nature of the design of our monitoring protocol is very well suited for regional-level observations on current reef conditions
the program is going to contribute to monitoring the current Diadema mortality event by adding a visual assessment of long-spined sea urchin health condition to our current monitoring protocol
So this work is going to occur along the entire Florida Reef Tract and the Flower Garden Banks which is in the Gulf of Mexico during this coming summer 2022 field season
What that means is that if divers observe Diadema
they will note whether the individual urchin is healthy
And then program field surveyors will essentially be acting as “eyes in the water” and report disease observations immediately to our partners and colleagues at the Atlantic and Gulf Rapid Reef Assessment
which has developed something called the Diadema Response Network
The Diadema Response Network is a collaboration of numerous organizations and individuals that are contributing information and guidance on how to monitor
how to respond to the Diadema sea urchin mortality event
HOST: Can these events be prevented in the future
because we don’t fully understand what’s causing the disease
it’s difficult to say how we might prevent these disease outbreaks from happening in the future
what we do know is that we can do our part to stop polluted runoff from smothering corals
And also reducing our carbon footprint by saving energy in our homes
And all these actions will help coral reef ecosystems be more resilient when they face new threats like disease
HOST: Are there other opportunities for the public to get involved in to help
TOWLE: If you live in Florida or the Caribbean and if you like to go diving or snorkeling, if you come across an urchin that looks sick or dying, you can report it to the Diadema Response Network by emailing them using the email address Diadema@agrra.org
you can make sure not to touch urchins or really any reef life for that matter
and rent your snorkeling or dive gear locally
make sure you clean and disinfect it properly after each use to be extra safe to reduce the chances of spreading the disease from reef to reef
HOST: And what about people who don't live near the ocean or who don’t dive or snorkel
TOWLE: The number one thing I’d say to that is you can educate other people about the importance of coral reef ecosystems and the threats they’re facing
I really believe that we can’t achieve conservation without an informed and engaged public
so one of the greatest things you can do for this cause is tell your friends
I’ll leave you with one piece of hopeful news which is that many scientists
even prior to this most recent disease outbreak
are working on active long-spined urchin restoration
which means urchins are grown in a laboratory aquarium until they are large enough
And what’s also really exciting is that coral restoration is also actively occurring
and if you’re interested in learning more about that you can visit NOAA’s Coral Restoration webpages
HOST: Be sure to check out our show notes to learn more about the Coral Reef Conservation Program
and how you can report healthy or sick sea urchins through the Diadema Response network
Subscribe to us in your podcast player of choice
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wedged between a quiet neighborhood and a mangrove forest
custom-designed aquariums are home to thousands of sea urchin larvae that tumble and drift through the water
Scientists with The Florida Aquarium and the University of Florida care for the little urchins
checking them daily under microscopes for signs that they’re maturing into juveniles
which look like miniature versions of the adults
For every one million embryos conceived in the lab
coral reefs in the Caribbean need all the urchins they can get
Long-spined sea urchins (Diadema antillarum) play a vital role in Caribbean coral ecosystems. While overpopulated urchins elsewhere are treated as villains—in California, for instance, divers smash purple urchins with hammers to keep them from mowing down kelp forests—Diadema are the Caribbean’s unsung heroes
Dark and rotund with spines radiating in all directions
the urchins eat massive amounts of algae that would otherwise smother corals or prevent coral larvae from affixing to rocks and growing into colonies
but they’re very effective at what they do,” says Alex Petrosino
a biologist at The Florida Aquarium and a member of the urchin lab team
bulbous skeletons with holes for wriggly tube feet and bumps where spines attach
Their mouths—equipped with limestone plates for scraping algae off hard surfaces—are in the middle of that skeleton
Petrosino calls Diadema the janitor of the reef because it’s so efficient at cleaning reef surfaces
Disease has killed roughly 97 percent of long-spined sea urchins across the Caribbean and as far north as Bermuda
endangering the corals that depend on urchins to rid them of harmful algae
an unknown ailment killed about 97 percent of Diadema urchins across the Caribbean and as far north as Bermuda
A later outbreak caused by a single-celled organism known as a ciliate further decimated urchins
The Florida Aquarium has teamed up with University of Florida aquaculture researchers to bring more sea urchins into the world
The team is raising long-spined sea urchins
and partners are releasing them into struggling reefs in Florida and beyond with the goal of developing methods that can be applied at a large scale
If it can be done efficiently and at scale
raising urchins in labs may jump-start populations of wild urchins in places where they haven’t been able to recover on their own
(Sometimes that’s because there aren’t enough adults left to reproduce
or because less coral leaves less urchin habitat
or because there are predators like crabs hiding in the algae that eat young urchins.) Researchers in Puerto Rico and the Caribbean island of Saba
And the idea is of interest beyond the Caribbean as well
now that another Diadema species in the Red Sea and the Indian Ocean is also being pummeled by a ciliate
The urchin rearing efforts share space with other projects run by The Florida Aquarium’s Conservation Campus
rescued sea turtles with illnesses and injuries peer through windows at the sides of colossal tanks
thousands of corals that may one day replenish Caribbean reefs quietly grow their colonies in broad
Tucked between these charismatic creatures is a multitude of sea urchins in various stages of life
“We have larvae in there right now,” says postdoctoral researcher Aaron Pilnick
There are thousands of baby sea urchins in the 40-liter tank
but they’re so tiny I see nothing but seawater through the glass
taking the microscopic urchin larvae on a nonstop ride
so they’d sink and die without continuously flowing water
or the larvae will run into each other—a problem for creatures as fragile as these
Each has two long arms jutting out from its tiny body
Some larvae have arms four millimeters long and a body only about half a millimeter wide
“That’s eight times the width of the body!” says Josh Patterson
a University of Florida aquaculture expert and urchin lab lead
We both take a minute to consider what life would be like with arms that long
Researchers with the University of Florida and The Florida Aquarium are figuring out how to raise microscopic long-spined sea urchin larvae in specially designed tanks
Photo courtesy of the University of Florida
“Their larval stage is extremely sensitive,” Patterson adds
He’s grown other types of urchins in an ordinary bucket
but Diadema need special care and superb water quality
unclean water sickened a batch of larvae; a veterinarian prescribed antibiotics and a full change of the water
To avoid dosing larvae with antibiotics again
Patterson and his team improved the water-cleansing system and added a huge UV filter to kill bacteria
is that “the larval stage is nothing like the adult stage.” Inside each larva
waiting to metamorphose like a caterpillar about to turn into a butterfly
it’s more like a spaceship carrying a little alien inside it
the larvae turn into miniature versions of the adults in four to six weeks
Patterson shows me a photo of a new urchin under a microscope
and comically enormous tube feet that the urchin will hopefully grow into
it’s about one millimeter across—no bigger than the point of a pencil
microscopic sea urchin larvae transform into miniature versions of adult urchins in four to six weeks
Photos courtesy of the University of Florida
shallow tanks in the greenhouses next door—the next stop in their journey to the sea—where they’ll grow without the threat of predators
the urchins sometimes share tanks with small coral colonies to help keep the coral algae-free
Pilnick points out a tank peppered with year-old urchins whose bodies measure less than 10 centimeters across
The tanks include blocks of rock and pieces of sliced PVC pipe that look like little urchin carports where the animals can shelter
Researchers hope the urchins will use these structures to behave nocturnally
hiding during the day and coming out at night to feed
this instinct helps urchins avoid being munched by crabs
or queen triggerfish “like little candy morsels,” as Pilnick puts it
some urchins are sheltering in the carports or under rocks and others aren’t
suggesting that not all of the lab-raised urchins have the instinct to hide
you behave differently as an urchin than you would on the reef,” Pilnick explains
“That could have some really big implications for things like predation or migration.”
Researchers with the University of Florida and The Florida Aquarium place lab-reared sea urchins into tanks alongside lab-reared corals
both may be released into the ocean to help replenish struggling reefs
An adjacent tank is brimming with about a dozen fully grown urchins collected from patch reefs near the Florida Keys
Pilnick picks one up by slipping beneath it a large two-pronged fork
a device designed specifically to move urchins around without getting pricked by poisonous spines
This is one of the parents of all the young urchins raised at the lab—5,403 of them as of April 2024
The number isn’t yet high enough to restore entire ecosystems
but Pilnick says it’s “leaps and bounds” ahead of where they started in 2018
a list of all the cohorts raised in the lab
they were consistently producing urchins; a cohort from late 2023 boasted over 1,800
Now that researchers have figured out how to raise Diadema
the next step is to learn what happens to those lab-raised urchins—and the ecosystems they support—in the wild
When researchers poured a cohort of young urchins into the shallow water of the middle Florida Keys in 2021
the spiky orbs scuttled about rocky and sandy patches of seafloor in search of shelter
They zoomed toward cracks between rocks and crowded below branching staghorn corals
urchin lab partners have released other cohorts and are studying how lab-raised urchins react in the wild
It’s not easy to track where the specific urchins go
Urchins can’t be tagged like other wildlife and are hopefully hidden during the day
but obviously still have a ton more to do,” says Patterson
He and Pilnick found that even sparse adult urchins—just one urchin for every six-and-a-half square meters of reef—can curtail algae
Urchins alone aren’t enough to save struggling coral reefs
But they can help buy time while people work to reduce greenhouse gas emissions and mitigate other drivers of climate change
But a lack of urchins and other grazers is just one of many problems affecting reefs
unprecedented heat in Florida and elsewhere in the Caribbean caused widespread coral bleaching and mortality
This was the start of a global bleaching event
the fourth ever documented and the second in the past decade alone
isn’t an excuse to not tackle climate change
Voracious urchins won’t prevent marine heatwaves or protect corals from bleaching
the urchins could help reefs bounce back after a heatwave
buying time while we reduce fossil fuel emissions
“We’re doing this one little thing over here to try to keep things together while these much larger issues get fixed,” Patterson says
The same is true in the greenhouse aquariums
the surfaces in the tanks would be coated with fuzzy green algae
Pilnick points out an urchin about the size of a pea that has scoured the algae from around a small coral
but it’s also creating space for the coral to grow
both creatures and their descendants may one day be part of a wild reef with habitat for a diverse array of vibrant
Part of the and family.
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Metrics details
The long-spined sea urchin Diadema antillarum was once an abundant reef grazing herbivore throughout the Caribbean
antillarum populations were reduced by > 93% due to an undescribed disease
This event resulted in a lack of functional reef herbivory and contributed to ongoing ecological shifts from hard coral towards macroalgae dominated reefs
Limited natural recovery has increased interest in a range of strategies for augmenting herbivory
An area of focus has been developing scalable ex situ methods for rearing D
The ultimate use of such a tool would be exploring hatchery origin restocking strategies
Intensive ex situ aquaculture is a potentially viable
antillarum at scales necessary to facilitate restocking
novel recirculating aquaculture system and the broodstock management and larval culture process that has produced multiple D
and which has the potential for practical application in a dedicated hatchery setting
Adult animals held in captivity can be induced to spawn year-round
with some evidence for annual and lunar periodicity
Fecundity and fertilization rates are both consistently very high
yet challenges persist in both late stage larval development and early post-settlement survival
Initial success was realized with production of 100 juvenile D
While the system we describe requires a significant level of investment and technical expertise
antillarum culture efforts in potential future hatchery settings and improves the viability of scalable ex situ production for population enhancement
coral gardening should exist within a larger restoration framework that aims to reestablish functional natural reef structure and biodiversity via a multi-niche ecological approach
antillarum restocking via hatchery produced animals
Stages include in situ broodstock collection from wild populations
larval development within scalable hatchery production settings
and in situ restocking on targeted coral reefs
Arrow colors depict current levels of success in achieving each stage; green = achieved reliably at large scale
yellow = achieved somewhat reliably at reduced scale
The transition from green to yellow depicts a shift from reliable
successful production of hundreds of thousands of late-stage larvae to relatively fewer metamorphically competent larvae at 28–35 DPF (days post fertilization)
The objective of this study was to develop successful rearing protocols for D
antillarum from gametes through larval settlement in a novel culture system with the potential for scalable production
Hypothesis-driven experimentation examining larval survival and growth in response to microalgae diet combinations
and initial larval stocking densities took place concurrent to this work
only the best performing treatments from each of these parameters are included in the below methods
antillarum broodstock were collected from patch reefs at ≤ 8 m depth off Marathon
Florida by the Florida Fish and Wildlife Research Institute under Florida Keys National Marine Sanctuary permit # FKNMS-2018-023 in March 2018
These animals were transported to shore in seawater-filled coolers and held temporarily in tanks with natural seawater
seawater-filled coolers to a land-based restoration aquaculture facility operated by The Florida Aquarium in Apollo Beach
These urchins were quarantined in an enclosed greenhouse for a 45-day period
during which visual health assessments were performed prior to introduction to established holding systems
animals were fed daily and maintained within the temperature range described below for long-term holding
Some individuals arrived in Apollo Beach presenting tissue and spine loss and were treated under the direction of a veterinarian with oxytetracycline hydrochloride baths (15 mg L−1 every other day for 1–2 h
14 surviving broodstock were transferred to 450-L fiberglass tanks within a 2380-L recirculating aquaculture system (RAS) designed and concurrently used to house Caribbean corals
and chemical filtration through the use of a protein skimmer
Water temperatures were maintained between 23.5 and 28.8 °C
Photoperiod varied naturally at the greenhouse latitude of N27° 46′ 43.81″
Nylon mesh was installed over portions of the tanks to provide shading (approximately 70% shading of incident light in greenhouse)
Salinity was maintained at 34–37 g L−1 using artificial seawater (ASW) prepared from reverse osmosis deionized freshwater and a commercial salt mixture (Tropic Marin
Broodstock were fed a commercially available herbivore diet ([34% crude protein
USA) five days per week in addition to grazing on benthic algae in the system
Broodstock were conditioned on the prepared diet for 2 months before successful spawning occurred
Group spawning was thermally induced following the methods described in Leber et al
One broodstock urchin died of an undetermined cause in the period after quarantine before spawning began
At each spawning attempt all (n = 13) broodstock were transferred to a 122-cm diameter polyethylene tank filled with 150-L of 1-μm filtered ASW
Water was heated to ~ 5 °C above holding tank temperature and supplemental aeration was provided
gametes were collected using 60-mL catheter syringes and transferred to a separate container with 1-μm filtered ASW
as well as the number of male and female animals spawning were recorded
sperm was not collected and instead allowed to diffuse throughout the tank
The residual sperm concentration in the spawning tank allowed for fertilization to occur as eggs were collected and transferred
If a female spawn occurred prior to a male
however an unquantified amount of sperm was then collected upon release from a male and transferred to the egg container for mixing and fertilization
Embryos were then transferred to a climate-controlled room where they remained in the mixing container for 1–2 h while water temperature cooled to match the larviculture system (25–27 °C)
embryos were moved to a single 40-L acrylic larviculture tank containing 1-μm filtered ASW and suspended in the water column using pulsed aeration
1-mL subsamples were counted using a Sedgewick Rafter cell to estimate total egg count and fertilization rate
Photograph depicting configuration of the 1800-L recirculating larviculture system used to rear D
Approximately 30% of total system water volume was exchanged weekly using 1-µm filtered ASW
Water quality parameters including salinity
and phosphate (PO43−) were monitored biweekly with a Hach DR 3900 spectrophotometer (Hach
Ammonia (NH3-N) was monitored intermittently using the same spectrophotometer
Salinity was also monitored multiple times weekly using a handheld meter (YSI Inc.
USA) and values were adjusted to a target of 35 g/L
Additional water samples were periodically sent to a commercial lab (Triton GmbH
Germany) for dissolved metal and total organic carbon (TOC) analyses via inductively coupled plasma optical emission spectrometry
antillarum development at (a) 2 h post fertilization
metamorphically competent late pluteus larvae with adult rudiment and extended tube feet
mid-metamorphic radially symmetrical juvenile resorbing bilaterally symmetrical larval structure
pre-conditioned ceramic tiles from broodstock holding tanks were additionally placed in larval culture tanks in an attempt to provide additional settlement cues
The tiles contained an assemblage of potential cues including crustose coralline algae
After juveniles settled in the culture tank and grew to approximately 1-mm in test diameter
they were transferred to separate 55-L glass tanks with pre-conditioned live rock and ceramic tiles
All spawning attempts used the same common broodstock pool
water temperatures were increased by 5.4 ± 0.3 °C (mean ± SEM) relative to the holding system temperature
Time from thermal induction to first gamete release averaged 3.6 ± 0.9 min
The proportion of individuals that spawned during each successful event was variable
ranging from 15.4 to 53.9% and averaging 34.3 ± 4.1%
The number of eggs extracted from each spawn ranged from 1.8 to 15.3 million with an overall mean of 5.0 ± 1.2 million
but fertilization rates were high and consistent at 94.0 ± 1.2% and no evidence of polyspermy was observed
While successful spawning events occurred throughout the calendar year
weak signals for both annual and lunar spawning patterns were observed
Simple linear regression revealed that the proportion of animals spawning in a given attempt was positively correlated with months relative to June (F (1
and negatively correlated with days since a new moon (R2 = 0.20
Larvae at 21 DPF were heavily pigmented and had characteristically long fenestrated postoral arm appendages reaching ~ 2-mm in length
A period of high larval mortality indicated by body condition deterioration and declines in larval density was observed in multiple culture attempts at 28–35 DPF
Larvae that survived these mortality events
developed adult rudiment appendages and well-defined tube feet at 28–93 DPF
Figure 3 (panels f–h) depicts larval settlement and juvenile urchin development
Following the addition of pre-conditioned ceramic tiles
competent larvae appeared to initiate settlement on biofilm surfaces within the culture tank and also on the tiles themselves
Sampled juveniles undergoing settlement were observed to resorb remnant larval appendage structures as they transitioned from bilaterally symmetrical plankton to radially symmetrical benthic urchins
Newly settled juveniles had orange and red tests and spines under top illumination and did not appear to have yet developed an Aristotle’s lantern feeding apparatus
Juvenile growth rates were highly variable despite low animal densities and high resource availability in the 55-L glass tanks
The most successful culture attempt resulted in a total of 100 juveniles surviving past 90 DPF from a single 40-L culture tank
This represents an 8.3% post-settlement survival rate from 1200 competent larvae
and a ~ 0.125% overall survival rate from the initial stocking of 80,000 larvae at 3 DPF
most juveniles appeared entirely black in coloration
Individual test diameters at 248 DPF ranged from 1 to 3 cm
Delayed settlement in subsequent successful culture attempts occurred at 60–93 DPF with a maximum of 49 juveniles produced per attempt
antillarum larval biology has prevented existing production methods from being applied and has necessitated a novel approach
The culture success described in this study was contingent on (1) a reliable non-invasive spawning procedure
and (3) reproducible larval rearing protocols
These methods have advantages and limitations
especially in the context of potential future D
with genetic contributions from only one male and one female
Thermal induction resulted in a low proportion of spawning individuals and
if used for scaled production and restocking
would necessitate housing and spawning an extensive number of broodstock in order to attain a minimal effective hatchery population size
Conducting future hatchery cohort parentage analyses could help to refine this approach
Avoiding potentially deleterious genetic intrusions will alternatively require targeted research aimed at increasing broodstock contributions to hatchery cohorts
If reliably high yields of juvenile urchins are attained from future larviculture attempts
revisiting the use of established yet destructive methods to enhance gamete extraction from broodstock could be justified
These methods may mitigate genetic risks inherent to a restocking program by improving hatchery genetic diversity
both seasonal and lunar cycles appeared to influence spawning performance in this study; however
these conclusions are uncertain given the small sample size
In situations where constant gamete production would be preferred
it could be conceivable to reduce cyclical spawning patterns by subjecting broodstock to constant photo-thermal parameters as described by Capo et al
Such a configuration has been anecdotally tested with D
antillarum in smaller tanks and resulted in larval mortality
While it is possible that increasing tank size could generate different results
antillarum larvae may be more negatively buoyant and less motile than C
the successful culture of this species in larger versions of the tank described here is unknown
Larger culture tanks with comparable geometry
flow rates and turbulence have the potential to further enhance larval production
it may not be necessary to do so as overcoming larval mortality bottlenecks within the system described could result in production of adequately high numbers of competent larvae from each tank
antillarum larvae are mechanically fragile
standard methods used to directly remove waste from culture vessels can cause mortality from breakage
The ability to flow treated recirculating water through the culture tanks mitigated the accumulation of waste products
Another consideration for system design was the necessity to minimize larval exposure to dissolved metals
The potential for contaminated source water was minimized by using artificial saltwater comprised of purified freshwater and a high-quality salt mixture
Dissolved metal concentrations were kept below known thresholds through weekly water changes
addition of metal adsorbing materials including granular ferric oxide and Poly Filter (Poly-Bio-Marine Inc.
low dissolved metal F/2 microalgae growth media
Future culture attempts could benefit from additional filtration methods to reduce dissolved metal concentrations
Standard water quality parameters were otherwise optimal
constant flow-through would also flush uneaten microalgae out of the larviculture tank and might result in diminished larval growth
antillarum larval settlement and post-settlement survival should be the subject of future research
Even moderate improvements in these areas will drastically improve the feasibility for mass production to meet restoration objectives
Further elucidation of settlement dynamics in the laboratory would also provide insight into the factors affecting settlement and recruitment in the wild and could improve our understanding of the limited D
Tandem restoration with reef-building hard corals should be explored as a potential solution to both provide predation refuge for urchins and improve multi-niche survival outcomes
The system described here incorporates tractable broodstock management and spawning
a RAS that balances requirements of a unique larval biology with the potential for experimental replication and scalable production
antillarum production within this system will necessitate an understanding of unknown bottlenecks causing larval mortality
The absence of observable water quality problems suggests that the most important issues facing the described system related to larval nutrition and/or disease
Continued culture attempts alongside strategic investigations into improved microalgal diets and disease dynamics will be necessary for further improving the viability of production for restoration
Although much more work is required before D
antillarum culture for population enhancement becomes a reality
the establishment of a balanced system design with reproducible results is an encouraging step forward
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This work was supported by a combination of funding from The Florida Aquarium
the University of Florida School of Natural Resources and Environment
the University of Florida School of Forest
and USDA/NIFA HATCH project #FLA-FOR-005902
Many thanks to our partners at the Florida Fish and Wildlife Conservation Commission for broodstock collection and collaboration
Funding was provided by Institute of Food and Agricultural Sciences
School of Natural Resources and Environment
All authors wrote and edited the manuscript
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DOI: https://doi.org/10.1038/s41598-021-90564-1
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Sea urchins in the genus Diadema (pictured
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Sea urchins enable complex reef ecosystems to thrive by eating algae that would otherwise smother corals
But that delicate natural balance is under threat in the Red Sea and Western Indian Ocean
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Volume 9 - 2022 | https://doi.org/10.3389/fmars.2022.1067449
The 1983-1984 die-off of the long-spined sea urchin Diadema antillarum stands out as a catastrophic marine event because of its detrimental effects on Caribbean coral reefs
Without the grazing activities of this key herbivore
turf and macroalgae became the dominant benthic group
inhibiting coral recruitment and compromising coral reef recovery from other disturbances
antillarum populations was slow to non-existent
We documented the spread and extent of this new die-off using an online survey
Infected individuals were closely monitored in the lab to record signs of illness
was surveyed weekly before and during mortality to determine the lethality of this event
Within four months the die-off was distributed over 1,300 km from north to south and 2,500 km east to west
Whereas the 1983-1984 die-off advanced mostly with the currents
the 2022 event has appeared far more quickly in geographically distant areas
First die-off observations in each jurisdiction were often close to harbor areas
suggests that anthropogenic factors may have contributed to the spread of the causative agent
antillarum were very similar to those recorded during the 1983-1984 die-off: lack of tube feet control
slow spine reaction followed by their loss
and necrosis of the epidermis were observed in both lab and wild urchins
Affected populations succumbed fast; within a month of the first signs of illness
had decreased from 4.05 individuals per m2 to 0.05 individuals per m2
antillarum die-off event is not currently known
The slower spread in the summer of 2022 might indicate that the die-off is coming to a (temporary) standstill
some populations will remain unaffected and potentially supply larvae to downstream areas and augment natural recovery processes
antillarum rehabilitation approaches have been developed in the past decade and some are ready for large scale implementation
active conservation and restoration should not distract from the primary goal of identifying a cause and
implementing actions to decrease the likelihood of future D
antillarum in the western Atlantic stands out for its sudden onset
and impact of the loss of a single species on entire ecological communities.”
in mid-February 2022 a local diver in St
Virgin Islands (USVI) posted images on social media of dozens of D
this die-off was thought to be a local event
antillarum from geographically separated Caribbean islands began to circulate in mid-March
To help coordinate efforts to investigate and disseminate information about this troubling new die-off
a group of Caribbean-focused researchers and managers created an open
In this first study by the Response Network
antillarum die-off and discuss similarities and dissimilarities with the 1983-84 die-off
as well as possible consequences for Caribbean coral reefs
Through use of social media and newspaper articles the USVI public was informed of the die-off and urged to make reports to the online database of healthy
were collected in the online database and reviewed to track the die-off spread in real time
All observations were verified via email or via submitted photos
Together with entries in the Diadema Health Tracking database (see below) this resulted in 209 observations of D
antillarum mass mortalities in St John and St Thomas
For the purposes of this publication local spread at these islands was documented through the end of May 2022
attachment to substrate and assessment of spine position) and Category Two behaviors (e.g.
as well obvious signs of epidermal lesions
Reports that lacked quantitative observations of more than several dead urchins and/or imagery depicting mass mortality were further assessed by requesting additional information from the contributors and
for any who were not already established reef observers
from local researchers or governmental representatives
the markers were coded green for healthy urchins
or remained purple for any reports with an unknown status
antillarum populations had recently disappeared were coded white
All site markers can be clicked to open a pop-up table of additional information and data
antillarum mass mortality in each jurisdiction (country or territory) is a proxy for its first occurrence in these locations
306 respondents in 34 jurisdictions (countries/territories) had submitted 582 reports and 426 photographs to the Diadema Health Tracking database
The Measure tool of ArcMap 10.8.1 was used to measure the distance between the first D
antillarum die-off at each jurisdiction and the nearest port
Entries in the database through 31 August 2022 were included in this paper
To determine the effect of the die-off on D. antillarum populations, pre- and post-die-off-D. antillarum densities were determined at dive site Diadema City in Saba, Dutch Caribbean (Figure 1)
which was destroyed by hurricane Hugo in 1989 and is now fully submerged with a depth range between 5 and 10 m
Diadema City is 100 m long and 10-20 m wide and contained the largest population of D
antillarum had been observed dying in Saba’s Fort Bay Harbor
three permanent transects of 30 m each were established at Diadema City
which is located 200 m upstream of the harbor and where no D
antillarum had yet shown any sign of illness
A base-line survey was conducted on 17 March 2022
antillarum within 1 m of the transect lines were inspected for any signs of illness and categorized as healthy or sick
Healthy individuals lacked all signs of illness and sick individuals had at least one of the signs described in more detail in the Results section of this study: lack of tube feet control
loss of spines and necrosis of the epidermis
The population was inspected for sick or dying D
antillarum twice a week and quantitatively monitored weekly for six weeks after the first signs of illness were observed
(A) Regional map shows the chronology of the die-off colored in bimonthly intervals from January to 31 August 2022
with the (B) northeastern Caribbean islands enhanced for clarity
B) represent the first observed outbreak date for each affected jurisdiction (country or territory) in sequential order
Ties (duplicate numbers) for identical first observed outbreak dates in two jurisdictions
(C) Saba and research locations Fort Bay Harbor (FBH) and Diadema City (DC)
(D) Local map shows the bimonthly die-off spread in the U.S
To determine the effect of the die-off on other sea urchin species
we recorded the post-die-off densities of D
antillarum and three other sea urchin species in Saba’s Fort Bay Harbor
A shallow breakwater (<2 m) of approximately 60 m2 contained a large D
along with individuals of the species Echinometra lucunter
Tripneustes ventricosus and Eucidaris tribuloides
The breakwater was surveyed for the first time on 18 March 2022
six days after local dive shop staff reported that urchins were dying in the harbor and three days after we confirmed this was the case
but large swells prevented an earlier survey
We categorized all observed sea urchins as healthy
Sick individuals had at least one of the signs of illness described above
antillarum were only recorded during the first survey
as swells and currents quickly washed away the skeletons
The survey was repeated weekly for nine weeks
Field observations were made of the dying D
antillarum juveniles (test size 12-37 mm) were grown-out in 12 static 70 L tanks in the Saba Research Center
The tanks were equipped with aeration and air driven sponge filters
receiving weekly water changes of 15 L with natural seawater
a water replacement was conducted with water from the harbor
Only later that day it was discovered that half the D
antillarum in the harbor were dead or dying
antillarum individuals that showed abnormal behavior were closely inspected twice a day and signs of illness were recorded in the order they occurred
No statistical interference could be performed on the Fort Bay Harbor counts
as this survey contained a single transect
Reported values are means ± standard deviation
During the first two weeks after initial observation of the D. antillarum die-off in late January, the spread seemed to be localized to southwestern St. Thomas but, by mid-February, reports of affected urchins were extending along the southeastern coast (Figure 1D)
at the same time as the die-off reached the neighboring island of St
more than 16 km away from the initial die-off site
the die-off quickly spread across the north coast and by early May it had enveloped the island
Eleven of the 25 first occurrences were within 1 km of the nearest harbor and 18 of 25 were within 3 km of the nearest harbor
Table 1 # on map (in chronological order
GPS location and distance to the nearest harbor of the first reported D
Before the die-off the average D. antillarum population density at Diadema City was 4.05 ± 0.68 D. antillarum per m2 (Figure 2)
During a biweekly inspection of the dive site
the first individuals with signs of illness were observed on 29 March 2022
Time after first observed signs of illness had a significant effect on the D
Nine days after the first signs of illness were recorded
antillarum density was reduced to 1.76 ± 0.99 individuals per m2
with 1.18 ± 0.53 healthy and 0.58 ± 0.47 sick individuals per m2
By 22 days after the first observed signs of illness
antillarum density was further reduced to 0.09 ± 0.03 healthy and 0.02 ± 0.02 sick individuals per m2
No sick individuals were observed during concurrent monitoring and the remaining D
antillarum population density fluctuated between 0.03 and 0.05 individuals per m2 for the remainder of the monitoring period
which was significantly less than the pre-die-off density (P<0.001)
Using the higher post-die-off population estimate of 0.05
this equates to a 99% mortality rate for the D
antillarum densities (mean ± standard error) at dive site Diadema City before and during the 2022 die-off
The D. antillarum population on a small breakwater in the harbor was surveyed for the first time on 18 March 2022 after large swells had prevented monitoring for six days after the first dead urchins were reported. D. antillarum densities were 1.32 healthy per m2, 0.18 sick per m2 and 1.38 dead per m2 (Table 2)
so the pre-die-off density was at least 2.88 D
tribuloides were also observed on the breakwater and all appeared healthy
although population densities of non-Diadema urchin species were not recorded on this initial survey date
antillarum density was reduced to 0.18 healthy and 0.07 sick individuals per m2
while other sea urchin species all appeared healthy
lucunter densities fluctuated between 0.33 and 0.9 individuals per m2
ventricosus densities between 0.03 and 0.05 individuals per m2
tribuloides densities between 0.00 and 0.07 individuals per m2
no sick or dying urchins were observed during the surveys in the Fort Bay Harbor
Table 2 Healthy and sick sea urchins (individuals per m2) in the Fort Bay Harbor
When field observations were made of abnormal D
antillarum individuals in Fort Bay and Oranje Bay on 15 March 2022
live individuals without visible signs of illness were found detached from the substrate and were swaying back and forth in the surge
Others had fallen from nearby vertical surfaces and were lying on their sides
Spine reaction of affected individuals was slower than usual and many individuals only reacted to physical stimuli after 2-3 attempts
A few individuals had epidermal lesions that exposed the underlying skeleton
these individuals did not exhibit spine movement
antillarum skeletons with and without mouth parts were found surrounded by detached spines
We suspect that those without mouth parts were due to opportunistic predation
as multiple fish species were observed attacking the impaired D
the abnormal individual had a very slow spine reaction when stimulated
The other three individuals were still able to move their tube feet and had a normal spine reaction in the afternoon
the disease had progressed in the other three individuals
who were not able to move their tube feet anymore
48 hours after the first observed signs of illness
many individuals showed signs of illness and subsequently died
Two weeks after the first signs of illness appeared in the lab
antillarum during the 2022 die-off as reported in this study
(B) Standing on spines not being able to use tube feet
(D) Tissue around broken spines sloughs off
antillarum die-off event that began in January 2022 is not currently known
and lethality span the spectrum of similar to dissimilar
What greatly differs are the location of the first occurrence and the pattern and speed of initial spread
The visible signs of disease and population density losses appear to be more similar
the 2022 die-off was first observed in the opposite quadrant of the Caribbean
antillarum mortality appeared in Jamaica (~1300 km to the west)
The near-simultaneous occurrence of dying urchins in such geographically separate areas suggests that the primary dispersal mechanism in the present event might be anthropogenic rather than current-driven
This interpretation is strengthened by the estimated distance of the first occurrence in each jurisdiction to the nearest harbor
18 were within 3 km of a harbor and 11 were within 1 km
The close proximity of the first observed mass mortalities to harbors for most jurisdictions reduces the chances of an alternative explanation for the near simultaneous outbreaks in different parts of the Caribbean
in which a causative agent was already widely present throughout the area in spring 2022
occurring at similar times in different jurisdictions
could have produced the distributional pattern that was observed
the causative agent of the die-off appeared to spread predominantly with surface currents
antillarum populations will be spared or at least persist for longer than the speed of the initial outbreak would have suggested
as long as the causative and dispersal agents of the mass mortality events remain unknown
it is impossible to predict the trajectory of the current or future D
It could be that during the 1985 die-offs in Panama and St
antillarum were direct survivors of the 1983-1984 die-off and had immunity against or insusceptibility to the original causative agent
At the moment of writing this manuscript (September 2022) the small breakwater in Fort Bay Harbor still harbors healthy populations of E
antillarum that were dying off around Florida in 1991
The similarity in signs of illness could either be an indication that the causative agent for the die-offs was the same or perhaps that echinoids have a limited repertoire of visible signs of illness
Oceanographic and meteorological conditions may also have initiated the 2022 die-off in some locations
as heavy rainfall was observed prior to the first mortalities at least in Aruba Puerto Rico
ambient weather conditions were reported to have been normal in the Dominican Republic
and Mexico when the urchins died and possible environmental correlates of the 2022 D
antillarum die-off warrant further investigation in follow-up studies
Differences between the 1983-1984 and 2022 mass mortality events included the location where each was first observed
their geographical spread and presumed primary dispersal modes
The rapidity with which affected populations succumb
effects on other urchin species and signs of illness were very similar
although the latter could be explained by a limited repertoire of visible illness responses
The different geographic spread might be explained by the increase in boat traffic in 2022 compared to 1983
The importance of boat traffic in the spread is emphasized by the close proximity to harbors of the first mass mortality in most jurisdictions
The initial speed of spread and broad geographic range of the 2022 D
it would eventually reach all areas of the Caribbean
few new jurisdictions have been affected since early May 2022
antillarum populations may remain unimpacted by this mortality event
due to the high lethality rate observed during the current die-off
antillarum may once again be functionally extinct on many Caribbean islands
There are at least three major differences between the aftermath of the 2022 and the 1983-1984 mass mortalities:
- Assuming the spread and/or lethality of the current die-off is reduced and certain parts of the Caribbean remain unaffected, there should be larger numbers of D. antillarum adults to contribute larvae to downstream areas. Thus, it is possible any natural recovery could occur faster than following the previous mass mortality event, when it took more than a decade before natural recovery was seen on most reefs (Lessios, 1995)
Preliminary quantitative data from Saba and Puerto Rico (A
unpublished data) and qualitative observations elsewhere in the region confirm that substantial settlement has occurred since the 2022 mass mortality event
Such improvements are likely to be lost in areas that were impacted by the 2022 die-off
those sites with previous densities of one per meter or more are now overgrown with turf algae (Personal observation M
antillarum die-off on reef structure and functionality will be exacerbated by increases in other stressors
for example the recent loss of corals due to SCTLD
lending to a more optimistic outlook than after the 1983-1984 die-off
As a causative agent responsible for the 1983-1984 die-off was never identified
the primary research priority for the 2022 die-off should be identifying its cause
Advances in technology and communication provide us with hope that this objective may be achieved
the next steps will be identifying and implementing actions to reduce the risk of similar events occurring in the future
The scale at which population rehabilitation will be required presents a massive challenge
but at least several rehabilitation approaches are already under development
we encourage proactive conservation and restoration efforts to preserve and enhance remaining populations
while continuing efforts to identify the cause of the 2022 mortality event and implementing actions to decrease the likelihood of future D
The raw data supporting the conclusions of this article will be made available by the authors
All authors contributed to the article and approved the submitted version
The Ocean Research and Education Foundation (ORE) funded the development and maintenance of the Diadema Dieoff Tracking Map and data platform
The fieldwork conducted on Saba was partly funded by SIA
part of the Dutch Research Council (NWO) in the context of the RAAK PRO Diadema project (project#RAAK.PRO03.005)
MV-R likes to acknowledge Consolidated Safety Services and the Puerto Rico Department of Natural and Environmental Resources for supporting her
We thank the many contributors who voluntarily submitted observations and photos to the tracking map
Their efforts have contributed to a greater collective understanding of the 2022 mortality event
We thank ORE’s Shirley Gun for her assistance to the Diadema Response Network
We want to thank the Saba Conservation Foundation staff
Bob Sesink Clee and Michael Nijlunsing for their help with conducting the sea urchin surveys
we appreciate the valuable comments and suggestions from the editor and two reviewers
which helped us in improving the quality of the manuscript
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Copyright © 2023 Hylkema, Kitson-Walters, Kramer, Patterson, Roth, Sevier, Vega-Rodriguez, Warham, Williams and Lang. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY)
*Correspondence: Alwin Hylkema, YWx3aW4uaHlsa2VtYUBodmhsLm5s
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Metrics details
As global warming and climate-change proceeds ever more rapidly
organisms depending on seasonal cues to synchronize reproduction face an unclear future
Reproduction in Diadema setosum in the Gulf of Aqaba (Red Sea) is seasonal
with mature individuals occurring from July to October
indicate that spawning occurs from August through December and suggests two main spawning events
indicate that the second peak of GI values cannot be related to spawning
but rather correspond to recovering individuals
examination of GI values alone may thus lead to erroneous conclusions
GI was moderately-strong positively correlated with sea-surface temperatures
but not with chlorophyll-a concentrations or photoperiod
Spawning coincides with the onset of the annual chlorophyll-a increase
which might be advantageous for nutrition of the developing larvae
First significant GI increase coincides with the shortening of day-length
Gametogenesis is highly synchronised between sexes
although the mature phase of females exceeds that of males
The non-complete overlap may represent sampling bias or represent an adaptive strategy for enhancing fertilisation success
n = 360) in the Gulf of Aqaba may be related to pollution
Distribution map and spawning periodicities of Diadema setosum
Here we provide the first report on the reproductive biology of D
setosum from the GOA with the aim of evaluating the environmental cues that control and synchronise gamete maturation and identify spawning periodicities in this species
we provide information on sex ratios in naturally occurring Diadema populations from two contrasting environments with (a) high (GOA) and (b) low (Zanzibar) levels of anthropogenic interaction and evaluate sexual differences in resource allocation between males and females in these environments
The sex ratios of Diadema setosum from the GOA deviated significantly from a ratio of 1:1 indicating that females are more abundant than males (96 males
in contrast to the equal ratio recorded in Zanzibar (199 males
No hermaphrodites were observed in any of the samples
Size and sex relationships in populations of Diadema setosum from the Red Sea (Eilat) and Western Indian Ocean (Zanzibar)
Linear regression models of diameter and weight (log transformed) in two populations of D
(b) Zanzibar and (c) the pooled data from both locations
Females are denoted by red circles; males by green triangles
Regression lines with 95% confidence interval are fitted for each plot and the corresponding equations and respective r2 and p-values are provided
is given below the corresponding equations
The reproductive stages of Diadema setosum from the Gulf of Aqaba
Histological photomicrographs of ovaries (a,c,e,g) and testes (b,d,f,h)
Cross-sections through acini representing reproductive stages I–IV
Stage I (spent): Gonads are largely devoid of contents showing ova-free lumen in females (a) and spermatozoan-free lumen in males (b) and may contain unspawned ova and spermatozoa undergoing lysis
A thin layer of NPs is present along the ascinal walls in both sexes and may form a pale meshwork across the ascinus
Stage II (recovering): NPs proliferate throughout the gonads from the ascinal wall to the centre
gradually filling the lumen of ovaries (c) and testis (d)
respectively and may occasionally project centrally
Stage III (growing): With the onset of vitellogenesis oocytes grow in size and become decreasingly basophilic
Both early and late vitellogenetic oocytes may be present along the ovarian wall and gradually migrate to the ovarian lumen as they mature (indicated by arrow) (e)
forming visible columns of darkly stained cells (f)
NP deplete and progressively occupy less space in both males and females
while oocytes at different maturation stages may still be evident in the germinal epithelium (g)
Occasionally some ova and spermatozoa may be evident in the coelom (h)
Ge germinal epithelium; C coelom; Po previtellogenetic oocyte; EVo early vitellogenetic oocyte; LVo late vitellogenetic oocyte; NP nutritive phagocytes; Ov ova; L lumen; Sc spermatocytes; Sz spermatozoa; Ps primary spermatocytes
The annual gametogenetic cycle of Diadema setosum from Eilat (Gulf of Aqaba)
ND corresponds to no data for that sampling month
Radial schematic plots provide a graphical representation of the transition and overlap of the different reproductive stages based on a monthly annual cycle
Temporal patterns of environmental gradients during the reproductive cycle Diadema setosum
Red line illustrates daily measured sea surface temperatures (°C) and green line illustrates daily measured chlorophyll-a concentrations (μg/l) fitted as a smooth curve (solid lines) and standard errors (shaded margins)
The smooth was calculated by local polynominal regressions
Temporal variation in ova and oocyte diameters
Diameters (μm) of ova (red boxes) and oocytes (gold boxes) from female Diadema setosum from the GOA
Measurements conducted from January 2010 through February 2011
Boxes represent monthly average oocyte diameters; centre black lines show the medians; box limits indicate the 25th and 75th percentiles; the 95% confidence interval of each median is represented by the notches and is defined as ±1.58 × IQR/sqrt(n) (with n representing the number of samples as indicated under the boxes); whiskers extend to minimum and maximum values with open circles representing outliers; width of the boxes is proportional to the square root of the sample size
Seawater temperatures abnormalities may also be driving the currently observed post-spawning increase in GI for D
as 2010 was significantly warmer than other years and in fact had the warmest winter on record since measurements began by the Monitoring Program at the Gulf of Eilat (Israel National Monitoring Program at the Gulf of Eilat
Diadema from the GOA seem to produce few excess oocytes per gametogenetic cycle and their spawning is most likely exhaustive
where spawning has been reported to occur in February and March
did not cover the entire annual cycle and reproduction in these areas may in fact still reflect a continuous pattern
an individual may improve its reproductive success by grouping with other conspecifics and tightly timing its reproductive effort to a short
exhaustive and highly synchronised spawning event
Echinometra refrains from straying away from their crevices and has never been observed to aggregate prior to spawning
In populations of relatively low densities
Echinometra may benefit from an extended spawning season during which local groups in the population
may spawn at different times during the season
triggered by the spawning of their nearby individuals
The current study is the first to demonstrate the reproductive cycle of D
It facilitates a geographical comparison with other localities of reported D
setosum reproduction and enables evaluation of the prevailing environmental cues that control reproduction in echinoids
the current study highlights potential pitfalls in the use of gonad indexes and the risk of drawing erroneous conclusions when GI data is not supported by histological analyses
Further studies of these important reef structuring echinoids are needed to facilitate comparisons over multi-annual cycles and elucidate the forces that drive biased sex ratio in echinoids
Twenty individuals of Diadema setosum were collected monthly along the coast of Eilat in the GOA (Red Sea, 29°32′48.1″N, 34°57′12.2″E; see Fig. 1) between January and December 2010
with an additional sampling conducted in February 2011
The samples were collected haphazardly by snorkelling at depths of 1 to 3 m and brought to the laboratory at the Inter-University Institute (IUI) in Eilat for further analysis
The largest corona diameter (measured at the ambitus)
corona height and wet weight of each specimen were recorded
Measurements to the nearest 0.5 mm were performed using thin-blade Vernier callipers to prevent interference by the spines
Weight was measured to the nearest 0.001 g after drying each specimen from excessive water for 5 min
After weighing and completion of external measurements
specimens were dissected and the gonads removed and weighed to the nearest 0.001 g (wet weight)
Sex was determined by observing a small piece of gonad under a light microscope and later confirmed using the histological sections
39°25′30.21″E) in the western Indian Ocean were added to the analyses to facilitate comparison with other Diadema populations
In total 260 and 414 specimens were analysed from Eilat and Zanzibar
corresponding to fluctuations in both the nutritive phagocyte (NP) and germ cell populations
Temporal variations in oocyte and ova diameters were assessed by randomly measuring 50 oocytes and/or ova of selected female specimens
Only primary oocytes sectioned through the nucleolus and ova sectioned through the nucleus were considered for this analysis
Monthly mean GI values of the different indexes calculated were tested against monthly mean SST
chlorophyll-a and photoperiod using Spearman’s rank correlation
Pairwise Kolmogorov-Smirnov tests were applied to test for monthly differences in size frequency distributions between oocytes and ova and p-values were adjusted for multiple testing to minimise false discovery rate
Monthly mean diameters of oocytes and ova were compared using permutation ANOVAs followed by Tukey’s honest significant difference (HSD) post-hoc test
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Larsson for their assistance in the field and laboratory
Brikner for assistance with the histological analysis and for fruitful discussions
We thank the Inter University Institute (IUI) at Eilat for providing laboratory and logistical support throughout this study
This research was supported by the Israel Science Foundation (ISF) to Y.L.
was partially supported by a postdoctoral fellowship of the Israeli Council For Higher Education and the Steinhardt Museum of Natural History
Israel National Center for Biodiversity Studies
Finally we thank the editor and three anonymous reviewers for their constructive comments that helped improve the manuscript
The authors declare no competing financial interests
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glass and colorful neon lights reminiscent of Miami's South Beach -- there's never a dull wall or unadorned ceiling aboard the 3,724-passenger Costa Diadema
it's decorated with ceramic or glass tile murals or eye-catching artwork
Even the cabin corridors sport colorful art from floor to ceiling
It's exactly what you would expect of Joe Farcus
renowned designer of many flamboyant ships for the Carnival Corporation
It's also what you would expect from Costa Cruises' newest
one dubbed "Regina del Mediterraneo" -- Queen of the Mediterranean
and there's more than enough razzle-dazzle onboard to call this Costa's crowning glory
there's an art collection of more than 7,000 works
those familiar with Farcus' previous designs will find Costa Diadema less brash and more
The theme of the ship is showcasing the best of Italy from pizza
Prosecco and gelato to dazzling entertainment and fashionable decor
Celebrating la dolce vita means such new features for Costa as the 1,640-foot open-air Promenade
considered to be akin to a real Italian seaside terrazzo (terrace)
The 16-foot-wide promenade surrounds the ship from front to back on Deck 5
Not only can you stroll completely around the ship
you can stop to relax in one of six outside cabanas linked to various restaurants and bars
and even take a dip in the two whirlpool tubs extending out from the ship's sides
innovative food and drink venues such as Tavola Teppanyaki
While knife-tossing chefs may be the standard of teppanyaki restaurants on land
spatulas make better juggling material at sea
You can sample hard-to-find Italian wines in the new wine bar
or taste a flight of Italian (and German) beers in the two-level beer garden
This is a party ship that comes alive from cocktail hour well into the wee hours
Italians (the majority of the passengers) and their fellow Europeans know how to live it up
including families with small children who go everywhere at all hours
Either you love being immersed in the European lifestyle onboard
or you're pining for familiar American ways of doing things
we wonder how the Europeans all manage to stay up so late and still head off on morning shore excursions on the port-heavy itineraries
Speaking of weeklong Mediterranean itineraries
cruisers have the option of embarking and disembarking at nearly every port of call
several hundred (or thousand) cruisers board and leave the ship on any given day
We overheard one Canadian passenger describe it as a floating hop-on
The good news is you can choose the air gateway (or train station for Europeans) that's most convenient for you
there's less crowding in each on/off port
The bad news is there's a lifeboat drill almost daily
accompanied by shipwide announcements in multiple languages
and there's little first-day sailaway fanfare
Other traditional cruise activities may be out of sync
which can be an issue for North Americans when there's a large European passenger base
is allowed indoors only in the Cigar Lounge
Smoking is OK in deck areas where there are ashtrays
you (or your neighbor) can smoke on the balcony
Europeans make up the majority of cruisers
North Americans are conspicuously in the minority
Announcements are given in at least five languages -- Italian
German and English -- and sometimes Portuguese and Chinese
only suggestions posted in the daily program
informal (jackets for men) or formal/gala which means cocktail dresses for women and jackets and ties for men
The late-night White Night deck party is the time to wear an all-white outfit
passengers are asked not to wear swimsuits at the buffet
European adults tend to dress less casually than Americans
Volume 9 - 2022 | https://doi.org/10.3389/fmars.2022.929355
This article is part of the Research TopicInnovative Approaches to Coral Reef Science by Early Career ResearchersView all 15 articles
The massive die-off of the sea urchin Diadema antillarum in 1983–1984 is one the main reasons for low coral recruitment and little coral recovery in the Caribbean
multiple restoration studies have been attempted
There are currently three different approaches to obtain individuals for restocking: the translocation of wild-collected juveniles or adults
lab-reared juveniles cultured from wild-collected settlers
or lab-reared juveniles cultured from gametes
All three methods are costly and can only be applied on a relatively small scale
which we term assisted natural recovery (ANR) of D
a concept already applied in terrestrial restoration to restore forests and grasslands
can accelerate succession by removing barriers to natural recovery
performed on the Dutch Caribbean island of Saba
suitable settlement substrate was provided in the form of bio ball streamers that were attached to the reef shortly before the settlement season
reefs with streamers had significantly higher D
antillarum recruit densities than control reefs without additional settlement substrate
indicating that the lack of settlement substrate is an important factor constraining natural recovery
antillarum recruit abundance was low compared to the measured settlement rates
possibly due to low post-settlement survival
The size distribution of recruits showed that recruits almost never became larger than 20 mm
low post-settlement survival and high predation on recruits also constrain the natural recovery of D
To improve the survival of settlers till adults
we propose to 1) reduce predation on settlers by using bio balls or other substrates that can provide shelter to larger individuals and 2) optimize the reef habitat by removing macroalgae
either manually or by facilitating other herbivores
we suggest to 1) choose sites with a known lower predation density or 2) protect recruits with a corral around the reef underneath the streamers
The combination of these measures could improve prospects for ANR
and we expect this new approach can contribute to the recovery of D
thereby reducing the ability of the coral reef to recover from disturbances
other factors seem to constrain the natural recovery of D
In contrast to using wild-caught individuals
headstarting collected settlers and culturing juveniles in the laboratory from gametes appear scalable
but the costs per juvenile remain relatively high
limiting the large-scale restoration potential of these methods
To circumvent the limitations of current restoration techniques
we here propose assisted natural recovery (ANR) as a new
ANR of D. antillarum might be possible if suitable settlement substrate is provided and/or if post-settlement mortality is reduced. Hylkema et al. (2022) compared five different types of D. antillarum settlement collectors. It was concluded that strings of plastic bio balls (Figure 2; hereinafter termed “bio ball streamers”) deployed mid-water were the most effective and reproducible method to monitor D
This study investigated if bio ball streamers attached to the reef shortly before the settlement season in an area with high potential settlement rates can enhance actual settlement and will result in an increased recruitment of D
this study aimed at providing insight whether the availability of suitable settlement substrate is the major barrier in the recovery of D
4) with streamers on which the transect tape is removed after monitoring
(B) Streamer with buoy and (C) Close-up of bio balls
Permanent markers were attached to both sides of the widest cross section of each reef to mark the monitoring area
and experimental surface area of the patch reefs
Caribbean Netherlands in the Caribbean region and location Ladder labyrinth
showing the positions of the experimental reefs and proxy streamers
To enhance D. antillarum settlement, nine streamers, consisting of 30 bio balls stringed on a fishing line (Figure 2), were attached to each treatment reef right before the start of the settlement season (Hylkema et al., 2022) in May 2021
The bio balls were 3 cm in diameter and made from polypropylene (PP)
The streamers were attached to stainless steel rings
which were epoxied into the reef matrix and kept upright using a small buoy on top
Streamers were approximately 1 m long and had a planar surface of 0.04 m2
The streamers were placed close to the transect line that was deployed between the two permanent markers
The experimental area was a band of reef 1 m to each side of the transect line
Used streamers were rinsed in fresh water for 24 h and sun-dried before they were redeployed at the next monitoring
antillarum settlers remained on the streamers and the suitability of streamers with a longer soaking time as a settlement substrate
six additional sets of three proxy streamers were deployed at the start of the experiment using the above-described methods
Three of these sets were retrieved and analyzed after 3 months and three after 6 months
antillarum recruits on all six experimental reefs was determined every month
starting at the beginning of the experiment (May 2021) and ending 6 months later (November 2021) for a total of seven monitoring events
A transect tape was positioned between the two permanent markers
and the area from 1m left to 1m right of the transect was thoroughly searched by trained observers for D
antillarum recruits using underwater flashlights
The test size of all recruits was estimated to the nearest millimeter using long-jawed calipers
The search time for recruits was standardized to 10 min per reef
excluding the time needed to record and measure the observed D
antillarum were left undisturbed on the reefs
Table 2 Estimated size range (mm), based on growth rates fromIdrisi et al. (2003) and Randall et al. (1964)
A one-way ANOVA was used to determine if the settlement on the proxy streamers differed by month
indicated non-normality of the residuals and heterogeneity of the variance
which was corrected for using a square root transformation of the D
Tukey post-hoc tests were performed to identify the months with significantly different settlement rates
A Kruskal–Wallis test was conducted to determine if soaking time of the streamers had an effect on the number of D
Streamers with a soaking time of 3 and 6 months (respectively collected in August and November 2021) were compared with streamers with a soaking time of only 1 month (collected in June 2021)
A post-hoc Dunn’s test was performed to detect differences in settlement densities for different soaking times
To assess the effect of streamers with a longer soaking time on new settlement
Mann–Whitney U tests were conducted to compare settlement on streamers with a soaking time of 3 and 6 months with streamers that had a soaking time of only 1 month
all of which were collected on the same day
All statistical analyses were performed with R (R Core Team, 2021) using R studio version 1.2.5001
All graphs were made using the R package “ggplot2.” P-values <0.05 were considered statistically significant and reported values are means ± standard deviation
After 1 month (in June 2021), the first D. antillarum settlers were observed on the streamers (Figure 3). The average number of D. antillarum settlers on the proxy streamers (Figure 4) differed significantly per month (P<0.001, Table 3)
Tukey post-hoc tests revealed that May (P < 0.004 for all comparisons) and June (P < 0.001 for all comparisons) differed significantly from all other months but not from each other (P = 0.239)
antillarum settlers was 8.6 ± 3.2 streamer-1 in May
and decreased to approximately 2–3 settlers per streamer for the remainder of the study
No significant differences were found between the other months
antillarum settlers per streamer per month
The line connects averages (± SE) and gray points represent the replicate streamers
Averages sharing the same letter were not significantly different
antillarum documented from a streamer in June falls outside the plotted y-axis limits but was used to calculate average (± SE)
Apart from the proxy streamers that were replaced monthly, 18 additional streamers were deployed at the start of the experiment, of which nine were retrieved after 3 months and nine were retrieved after 6 months. Soaking time had a significant effect on the number of settlers (P < 0.001, Table 3)
This decreased significantly to 0.2 ± 0.4 after 3 months
collected at the end of October 2021 (P < 0.001 for both comparisons)
Streamers retrieved after 3 and 6 months did not differ significantly in their number of D
Settlement on streamers with a soaking time of 3 and 6 months was also compared with streamers that were collected on the same day but had a soaking time of only 1 month. In July 2021, streamers with a soaking time of 1 month had 1.8 ± 1.4 D. antillarum settlers per streamer, which was significantly higher than the 0.2 ± 0.4 per streamer with a soaking time of 3 months (P = 0.004, Table 3)
streamers with a soaking time of 1 month had 0.8 ± 0.8 D
which was not significantly different to streamers with a soaking time of 6 months
D. antillarum recruit abundance on the patch reefs (Figure 5) was significantly affected by treatment (streamers vs. control, P = 0.032, Table 3), month (P = 0.001, Table 3), and their interactive effect (P = 0.042, Table 3)
Monitoring area had no significant effect on the D
antillarum recruit abundance as was not included in the best-fitting model
reefs with and without streamers both had zero D
antillarum recruit abundance increased on all six patch reefs
when reefs with streamers had an average of 4.3 ± 3.2 D
antillarum per reef and control reefs had an average of 2.7 ± 2.1 D
antillarum density at the treatment reefs was
significantly higher than at the control reefs (P = 0.007)
this effect had strengthened: reefs with streamers had on average 6.3 ± 5.9 D
which was more than 20 times higher than control reefs without streamers
This difference was highly significant (P = 0.001)
antillarum density on treatment (with streamers) and control (without streamers) reefs as a function of time
Lines connect averages ± SE and * indicates a significant difference in treatments for that month
Figure 6 shows the D. antillarum recruit size distribution per monitoring month (July–October). The average D. antillarum recruit size was not affected by the monitoring month (P = 0.068, Table 3) or treatment (not included in the best-fitting model)
antillarum recruit size was 10.3 ± 3.5 mm
which corresponded with settlement in April
recruits had a similar average size (11.8 ± 4.0 mm) and their size distribution corresponded most closely with settlement in May
the average recruit size was 13.4 ± 5.1 mm
Half of the recruits were approximately 20 mm; these where likely the remaining recruits from the cohort settling in May or possibly April
The other half of the recruits were smaller and had probably settled in June or July
the average recruit size was 10.7 ± 4.5 mm and most of the recruits corresponded in size most closely to the predicted size range for settlement in July or even August
Figure 6 D. antillarum recruit size distribution on control and treatment reefs per monitoring month. The area between vertical lines of the same type (dashed, solid, dotted, etc.) indicate the estimated size range per settlement cohort, based on growth rates from Idrisi et al. (2003) and Randall et al (1964)
We observed abundant turf and macroalgae growth on the 3- and 6-month old bio balls
which probably made the bio balls less suitable for settlement
this means that streamers older than 2 months attract less new D
notwithstanding increased settlement due to the streamers
the high predation of larger juveniles might have reduced post-recruitment survival and prevented D
antillarum (black arrows) and factors constraining (red arrows) or enhancing (blue arrows) D
Factors with an asterisk (*) likely affected D
antillarum recruitment in the present study
we expect ANR to be able to contribute substantially to D
antillarum population recovery in the near future
Writing - Review & Editing EP: Investigation RO: Writing - Review & Editing AM: Writing - Review & Editing
We declare that all sources of funding received are submitted
This research was conducted in the context of the RAAK PRO Diadema project (project# RAAK.PRO03.005)
(Dolfi) Debrot were funded by Wageningen Marine Research through project 4311500013 R&D Wetenschapsplan
and Jasper Bleijenberg for assisting with the recruit counts and the analysis of the proxy streamers
for providing fieldwork assistance and Callum Reid for making the map
We want to thank the two reviewers for their feedback and suggestions on an earlier version of this manuscript
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Osinga R and Murk AJ (2022) Assisted Natural Recovery: A Novel Approach to Enhance Diadema antillarum Recruitment
Received: 26 April 2022; Accepted: 07 June 2022;Published: 15 July 2022
Copyright © 2022 Hylkema, Debrot, van de Pas, Osinga and Murk. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY)
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antillarum reintroduction may therefore be successful
if coupled with the artificial augmentation of 3D habitat complexity
although our current understanding is based largely on correlative analyses and urgently needs to be supported by experimental evidence
and they must also have room for their articulated spines
We then use an ex situ lab-based experiment to address the hypothesis that D
antillarum demonstrate behavioural changes in the presence of enhanced habitat complexity that reduce energetic requirements associated with predator avoidance and thus improve survival potential
we use our findings to justify the deployment of a network of simple and cost-effective artificial reefs
designed to provide optimal habitat complexity to both juvenile and adult D
Our results support the hypothesis that enhancement of reef structure can augment D
antillarum populations as we report significant increases in densities over a 24-month period relative to nearby control reefs
We investigated the importance of habitat structure to D
antillarum population dynamics using two in situ field studies and an ex -situ lab-based experiment
The in situ studies allowed us to explore the impacts of habitat structure on D
whilst the ex-situ study enabled elucidation of the mechanisms that may drive the relationships observed in the field
making it one of the healthiest reef systems in the Caribbean
an 822.6 km2 area of the bay was afforded protection by the Honduran government as part of the El Refugio de Vida Silvestre Marino de Tela
Habitat complexity was measured within 2 × 2 m quadrats placed randomly on six reef sites along the south shore of the island at depths of 8–10 m
antillarum was recorded in each quadrat; 35 quadrats without urchins were assessed and a further five urchin-containing-quadrats were sampled to allow complexity differences to be elucidated
were accounted for in the statistical analyses
can be extracted from 3D models at different spatial scales
allowing researchers to gain a better understanding of the importance of 3D architecture to their study organism
3D models were built based on video scans of the quadrats
filmed from a birds-eye perspective with a single camera (GoPro Hero 4 Black) held approximately 50 cm above the substrate
The quadrat was swept in a lawnmower pattern
ensuring a minimum overlap of 25 cm between passes; essential for successful image alignment and model construction
Videos were converted to still images using QuickTime Player v.7.6.6 (QuickTime 1989–2010) at an extraction rate of 3 frames per second which generated 450 to 540 still images per quadrat
These images were uploaded to PhotoScan Pro v.1.3.2 (Agisoft PhotoScan Professional 2017) and 3D models constructed
Resultant PhotoScan files (.psx) were converted to object files (.obj) and imported into Rhinoceros 3D 5.3.2 (Rhinoceros 1993–2017) for analysis
To identify spatial scales that are ecologically relevant to local D
antillarum populations with regards to predator avoidance
antillarum at our two study locations in Utila (n = 139) and Tela Bay (n = 100)
we searched the reef for adult urchins and coerced them from their crevice using a 50 cm length of PVC pipe
of each individual was measured using a long-jaw calliper
The in situ habitat structure preference study elucidated that D
antillarum prefer complex habitats at the 5–15 cm spatial scale
We therefore conducted an ex situ lab-based study to try and identify the mechanisms that may drive this relationship
Panel photograph showing tank setup for different complexity treatments
top right = artificial-material-low-complexity
bottom left = natural-material-high-complexity
bottom right = artificial-material-high-complexity
The location of the reef material in the tanks was assigned prior to each trial using a random number generator to control for the position effect
50 black adult urchins were tested under 5 different experimental treatment combinations in a fully factorial design (n = 10 for each combination)
Each urchin was used for a single trial only
Six trials were completed daily and the treatment combination in any given tank was randomised along with the treatment order to control for potentially confounding variables
Banco Capiro may be one of the healthiest reefs found in the Caribbean today
Individuals were removed from the reef using a 50 cm length of PVC piping
retained for a maximum of 24 h and returned to the site of their collection the following morning
Pseudoreplication was avoided by returning urchins to a different sub-site of the reef from where new specimens were collected
Prior to commencement of trials urchins were placed in 300 L glass holding tanks maintained at ambient SST in the laboratory for at least eight hours
antillarum is a priority throughout the Caribbean
and so short acclimatisation periods were used to minimise the risk of mortality caused by experimentally induced stress
antillarum was placed in the trial tank and allowed to settle for 30 min
they quickly moved towards the structure in the tank
placed in the tank and positioned to focus on the urchin
Predator avoidance behaviour (PAB) was defined as the number of spines that move in response to the shadow stimulus as a percentage of the total number of long defensive spines visible in the video
This effectively standardises the measure between urchins and negates the problem that some long spines may be obscured by structures in the tank
Videos were analysed in a random order to avoid observer bias
antillarum test diameters in Tela Bay suggested 10 × 10 cm diameter holes would provide suitable refugia for individuals at the lower end of the test size range (i.e
likely new recruits to our artificial reefs)
Three-dimensional images showing complexity differences between: (A) a 2 m × 2 m area of reef without urchins on Utila
(B) a 2 m × 2 m area of reef with urchins on Utila
(C) a 2 m × 2 m area of control reef in La Ensenada
(D) an artificial reef deployed at La Ensenada
D(5–15 cm) = fractal dimension of the model at the 5–15 cm spatial resolution
but all artificial reefs are identical therefore variation in fractal dimension for (D) is not reported
and for percentage cover of macroalgae using CoralPointCount (CPCe) software with 100 points randomly overlaid on each image
Percentage cover of mature scleractinian coral was not examined due to the relatively short (24 month) timeframe of this project meaning genuine changes were unlikely to be reliably detectable
Randomly placed 50 × 2 m belt transects created a 100 m2 survey area in which D
antillarum and juvenile coral recruit abundances were recorded
Benthic percentage cover was calculated using point-intercept video transects analysed at 0.25 m intervals
Two transects were carried out on control reefs located at least 100 m away from any of the ARs at each sub-site (n = 6)
The methods used to assess the relative changes around the artificial and control reefs differed
Transects allowed us to survey a large area of the control reef to gain an accurate understanding of the background patterns of change
but they were not appropriate for assessing localised changes within 5 m of the AR structures
these data are not directly compared statistically
The first part of this study used fractal dimension (D) as a proxy for structural complexity to explore the in-situ habitat preferences of D
We assessed differences in D between quadrats inhabited by D
which are robust to unbalanced survey designs
We conducted one test for each of the five spatial resolutions (1–5 cm
and adjusted the results for multiple comparisons using the Bonferroni method
Predator avoidance behaviour was evaluated as a function of reef complexity (flat
and reef material (natural and artificial)
and their interaction using a two-way analysis of covariance (ANCOVA)
Post-hoc Tukey–Kramer analyses were used to assess pairwise differences in PAB among treatment combinations
Visual analysis of the residuals revealed that there were no influential outliers
the data were independent and normally distributed
therefore parametric analyses were considered appropriate for these data
antillarum test diameters on the reefs of Utila (yellow; n = 139) and Tela (blue; n = 100)
Dotted vertical line is the mean of all individuals from both locations
Complexity signatures of reef areas devoid of D
Data shown in the main panel are mean ± 1SE fractal dimension (D)
a measure of structural complexity within defined spatial resolutions
with 5–15 cm representing the size range of ecological significance to D
D ranges from 2 to 3 and higher values are associated with greater structural complexity
Impacts of habitat complexity on the predator avoidance behaviour (PAB) of D
Flat treatments were carried out in trial tanks without any structure
low complexity treatments with natural material occurred in tanks enriched with fragments of reef rubble
and low complexity treatments with artificial materials were conducted in tanks with fragmented breezeblocks
High complexity treatments with natural material used reef rubble to simulate a reef crevice
and during high complexity treatments with artificial material individuals were provided with a whole breezeblock
The study was fully factorial and n = 10 for each treatment
The bold horizontal line on each boxplot represents the mean
the box itself shows the interquartile range and the whiskers delimit the full range of the data
Letters above the plots show the result of a post hoc Tukey–Kramer analysis and show where significant differences between treatments occur
At the start of this study, the degraded reefs of La Ensenada exhibited fractal dimension of the ecologically relevant 5–15 cm spatial range (D5–15) of 2.08 ± 0.01. This compared to 2.14 ± 0.01 for Utila’s reefs without urchins, and 2.22 ± 0.04 for Utila’s reefs with urchins. With the addition of our artificial reefs, this complexity was increased to 2.16 ± 0.00 (Fig. 2)
Fractal dimension (D) used as a proxy for 3D structure gives a value between 2 (perfect 2-dimensional surface) to 3 (perfect 3-dimensional surface) therefore the 2.08 to 2.16 increase associated with the deployment of the artificial reefs represents a 100% increase in habitat complexity
Temporal changes in the density of adult and juvenile D
antillarum on small artificial reef structures and nearby control reefs
Data were collected at the same time each year
but points are jittered to aid visualisation
Prior to AR deployment, control reefs exhibited mean macroalgae cover of 21.58 ± 0.50% and juvenile coral recruit densities of 3.38 ± 0.69 m−2 (Table 4)
They showed no subsequent significant change in macroalgae cover over the course of this study
but the abundance of juvenile coral recruits decreased by 50% in the first year
and a further 47% in the second year (X2 = 12.00
By contrast, within a 5 m radius of the ARs, macroalgae cover decreased from 56.07 ± 1.19 to 52.92 ± 1.04% in the first year, and again to 38.13 ± 0.91% in the second year (X2 = 122.88, p < 2.2 × 10−16) representing a 17.94% reduction in actual percentage cover (Table 4)
There was no significant change in the abundance of coral recruits throughout this time period
despite the significant decline on nearby control reefs
in a complex habitat where the defensive role of PAB is
Artificial reefs may therefore stimulate D
antillarum population recovery not only by reducing vulnerability to predation
but also by decreasing nearest-neighbour distances and increasing resource allocation to reproduction
both of which will help overcome the Allee effect that contributes to their continued suppression
that our ecological surveys suggested that the colonisation of ARs by D
antillarum over the 24-months of this study stimulated both a significant decrease in macroalgae cover compared to adjacent control reefs
and maintained stable juvenile coral recruit densities against a backdrop of declining densities on control reefs
A longer time series would be needed to determine whether these initial benefits translate into longer-term increases in mature scleractinian coral cover
This highlights that for reintroduction to be successful
the factor(s) preventing recovery must first be removed
The findings we present here suggest that the augmentation of structural complexity that accompanies the deployment of ARs may mitigate a major barrier to population recovery and increase the success of D
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We would like to thank all the Operation Wallacea staff and volunteers who helped with data collection and logistical support for this project
and the Honduran Government’s Instituto de Conservación Forestal (ICF) for permission to conduct this research
We also thank staff at Tela Marine Research Centre and Coral View Research Centre
This work was possible thanks to a PhD studentship to MB funded by Operation Wallacea
All authors reviewed drafts of the manuscript
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DOI: https://doi.org/10.1038/s41598-021-87232-9
is an ecologically important species in Caribbean coral reef habitats where it controls algal growth and coverage and helps keep reef surfaces clear for corals to grow and settle
antillarum populations began experiencing mass mortality in the Caribbean
a healthy urchin is seen on the left with spines intact
another urchin is in the process of losing its spines—which usually occurs within 1-2 days of infection.
With reefs already under tremendous stress from changing environmental conditions
identifying and stopping the spread of this fatal urchin event is critical for protecting coral reefs into the future
James Evans and Christina Kellogg are part of an international team working to identify the pathogenic microbe—a critical first step to addressing this disease and helping managers develop effective disease mitigation strategies
The parasite that was identified as the cause of Diadema antillarum sea urchin mass mortality in the Caribbean in 2022 has been shown to be the cause..
A fatal pathogen affecting the long-spined sea urchin decimated populations of this important herbivore in the 1980s
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Herbivores control algae and promote coral dominance along coral reefs
the majority of previous studies have focused on herbivorous fish
Here we investigated grazing effects of the sea urchin Diadema savignyi on algal abundance and coral recruitment processes
We conducted an in situ cage experiment with three density conditions of D
m−2) for three months during the main coral recruitment season in Taiwan
Results demonstrated a strong algal control by D
m−2 declined by one third compared to 0 indiv
savignyi was observed on coral recruitment processes
the density of coral recruits declined and mortality of small coral fragments (proxy of coral juveniles) increased
Our results confirm findings of previous studies and indicate the need to balance both positive (strong algal control) and negative (physical damage) influences of Diadema grazing to facilitate the coral recruitment process
far less attention has been paid to non-fish herbivores
sea urchins and gastropods (except Diadema antillarum in the Caribbean)
These findings motivated us to examine the effect of Diadema grazing on algal control and the coral recruitment process
as a primary driver of the observed correlations
using the locally dominant Diadema species
coral recruit density and growth and the survival of small coral fragments (proxy of coral juveniles) were examined under three density conditions of D
(a) Study location of the inclusion cage experiment at Nanwan bay, Kenting, Southern Taiwan. The area enclosed by the dashed line indicates Kenting National Park. The map was created using the package, maps ver. 3.3.0 with the software, R ver. 3.6.1 (https://www.rdocumentation.org/packages/maps/versions/3.3.0)
(b,c) Image of the inclusion cage experiment: (b) two of the five experimental cage groups
each consisting of three cages for three D
savignyi density conditions on the top of plastic container base; (c) close-up of two cages with 8 indiv
Each cage had 12 experimental terracotta plates (10 cm × 10 cm) fixed on the mesh bottom
Five groups of experimental cages were established as replicates at a distance of ca
2–3 cm in diameter) were collected from five different donor colonies at the study site and introduced into the three density condition cages in each of the five groups (i.e.
n = 5 fragments from different colonies per density condition)
Coral fragments were fixed on separate plates using super glue
The relative growth rate of each fragment was calculated by dividing the increased (or decreased) tissue area over the 3-month experimental period by the initial tissue area
the glm.binomial.disp function of dispmod ver
1.5.5 package for constructing the zero-inflated poisson model
During the 3-month experiment, the weather was calm and seawater temperature was 26.9 ± 1.2 °C (mean ± SD). There were two sea urchins that died, two escaped and one moved into another cage due to a mesh breakage (Supplementary Table S1)
These cases happened once in two cages and twice in two cages
the sea urchin density was restored to the original density within 1 month
The effect of three density conditions of Diadema savignyi on algal cover during the 3-month inclusion cage experiment
Stars indicate statistical significance at p < 0.01 (**) and p < 0.001 (***); (a) between the three density conditions from the 1st to 3rd month
m−2 at the 1st month and between the three density conditions at the 2nd and 3rd month
and (c) between the three density conditions at the 1st month
Datapoints were slightly shifted horizontally to avoid overlapping
Algal biomass at the end of the 3-month experiment was significantly lower at higher density conditions of D. savignyi (Fig. 3). The average algal biomass in the 8 indiv. m−2 condition (0.5 g 100 cm−2) was one third of that in the 0 indiv. m−2 condition (1.5) and was close to zero in the 16 indiv. m−2 condition (0.02).
The effect of three density conditions of Diadema savignyi on algal biomass at the end of the 3-month experiment
Stars denote statistical significance at p < 0.05 (*) and p < 0.001 (***)
The effect of the three density conditions of Diadema savignyi on coral recruitment density (a) on grooved surface plates and (b) plane surface plates at the end of 3-month experiment
Stars denote statistical significance at p < 0.05 (*) and p < 0.01 (**)
No coral recruits occurred on plane plates in the 16 indiv
Growth of coral fragments at the end of the 3-month experiment were compared between the density conditions of D. savignyi for each species (Supplementary Fig. S2)
no significant difference was found between 0 and 8 indiv
a significantly higher growth rate was detected in 8 indiv
and indicates the need for density control when considered for coral reef management
Although these studies examined the effects of Diadema grazing together with other coinhabiting herbivores in the field
the results generally support the strong capability of algal control by Diadema species
Results of algal cover indicated approximately a 50% reduction in 1 and 2 indiv
m−2 conditions and nearly a 100% reduction in 4 and 8 indiv
Algal biomass was reduced to one tenth in 1 and 2 indiv
m−2 conditions and nearly zero in 4 and 8 indiv
the results indicate a high variation in effective Diadema densities on algal control among cases
This is likely owing to differences in local conditions (e.g.
nutritional and physical environment and algal assemblage) and examined Diadema species
suggesting that it may be necessary to examine effective Diadema density at each location
which may also vary with time as local conditions change
the current limited information suggests that
the maximum Diadema density of ≤ ~ 8 indiv
m−2 would benefit coral recruitment processes
controlling algae and enhancing coral juvenile density
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Grazing by the echinoid Diadema antillarum Philippi: formation of halos around West Indian patch reefs
Grazing and control of coral reef community structure by Diadema antillarum Philippi (Echinodermata: Echinoidea): a preliminary study
Effects of grazing by Diadema antillarum Philippi (Echinodermata: Echinoidea) on algal diversity and community structure
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Effect of sea urchin (Diadema setosum) density on algal composition and biomass in cage experiments
Incorporating herbivorous sea urchins in ramet culture of staghorn coral Acropora cervicornis
Ecological complexity of coral recruitment processes: effects of invertebrate herbivores on coral recruitment and growth depends upon substratum properties and coral species
Grazers improve health of coral juveniles in ex situ mariculture
Mespilia globulus and the coral Acropora millepora enhances early post-settlement survivorship
Local and regional scale recovery of Diadema promotes recruitment of scleractinian corals
Survivorship of fast-growing coral spats depend less on refuge structure: the case of Acropora solitaryensis
Grazing by a small fish affects the early stages of a post-settlement stony coral
Effects of predators and grazers exclusion on early post-settlement coral mortality
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and Tzu-Yu Lai for equipment preparation and support with the experiment in the field
Aziz J Mulla kindly edited English in the manuscript
Comments from the editor and two anonymous reviewers improved the manuscript
The study was funded by the Ministry of Science and Technology (106-2611-M-001-004
107-2611-M-001-003) and an internal research grant from Biodiversity Research Center
Academia Sinica and National Taiwan Normal University
Institute of Marine Environment and Resources
Graduate University of Sciences and Technology
conceived and conducted the research and wrote the manuscript
assisted with administration and field investigation
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DOI: https://doi.org/10.1038/s41598-020-77494-0
Earlier this year, Bill Paley, La Palina’s chairman, celebrated his 75th birthday, and as cigar companies are wont to do, a new blend was created to commemorate the occasion. The La Palina 1948—named after Paley’s birth year—debuted in four box-pressed vitolas during the 2023 PCA Convention & Trade Show
and while three of the sizes are regular production
the Diadema viola is limited to 500 boxes of 10 and was sold exclusively to retailers who attended and placed orders at the 2023 PCA Convention & Trade Show
While the wrapper covering the blend is a sun-grown Sumatra leaf grown in Ecuador that has been aged for two years
both the binder and filler tobaccos were sourced from Oliva Cigar Co.’s farms in Nicaragua
Oliva was enlisted to make the cigars at its TABOLISA factory that is located in Estelí
“I am thrilled to have been able to bring this cigar series to life, as it honors both my family and our company,” said Bill Paley in a press release
My grandfather was a key figure in starting the company
and this cigar is also a tribute to his legacy and our continued success.”
The La Palina line currently includes four box-pressed vitolas:
The combination of a dark brown wrapper and fairly unique vitola makes the La Palina 1948 Diadema is an attractive cigar from a visual perspective
The wrappers have almost no oil or tooth at all
but they are covered in overt veins and also have a multitude of bumps all over them
all three cigars are nicely spongy when squeezed
but I find a small soft spot on the back of the cigar in-between the band and the feet on two of the cigars
Aromas from the wrappers include a very obvious sweet earth note along with some generic woodiness
aromas from the feet of the cigars are very similar to those emanating from the wrappers
but I do notice that the woodiness is pronounced to remind me of oak
and there is some additional vanilla sweetness
the cold draws bring flavors of peanut butter
The small feet of the La Palina light up quickly and immediately bring notes of light spice
but those quickly fade as the main flavor combination of peanuts and hay takes over the profile
earth and creamy oak show up at various points
but one of the cigars features a slight vegetal note that becomes a bit more noticeable as the first third burns down
All three cigars feature the same combination of light white pepper and vanilla bean sweetness on the retrohale
and while neither note is all that aggressive at the moment
The flavor ends the first third at a solid medium
while both the body and strength lag behind at mild plus and just under the medium mark
There are absolutely no issues when it comes to construction
smoke production and draws are all performing wonderfully so far
Dry hay and creamy peanuts continue to reign supreme in the profile of the cigar during the second third
followed by secondary flavors of dark chocolate
the creamy oak flavor from the first third has become noticeably more generic—I would describe it as a general woodiness now—but the vegetal note present on one cigar has grown a bit stronger
and there is virtually no change to the vanilla bean sweetness and black pepper that is present on the retrohale
Flavor bumps up slightly to land at a point just over the medium
the body increases to just under the medium and the strength increases to a solid medium
the draws and smoke production continue to be trouble-free for all three cigars
but all three do need corrections with my lighter to stay on track
The final third of the La Palina 1948 is a virtual carbon copy of the second third when it comes to flavors
as the creamy peanuts and hay combination have no problems holding on to the top spot until the end of the cigar
There are also a few surprises in the secondary flavors—a list that includes the familiar generic wood
the latter of which is still made up of the same combination of black pepper and vanilla sweetness
The flavor ends the cigar at just over medium
but the body increases enough to hit a solid medium
and the strength bumps up ever-so-slightly to move to a point slightly above the medium mark
the construction for all three cigars has reverted back to what it exhibited in the first third
meaning there are zero issues with the burns
and I put the nubs down with about an inch remaining
As someone who is approaching the 50-year mark much too quickly
I can appreciate the idea of celebrating a 75th birthday with a new blend
The La Palina 1948 Diadema is a worthy addition to the company’s line-up
with enjoyable flavors of creamy peanuts and dry hay on the palate that are accentuated by vanilla bean sweetness and black pepper on the retrohale
Each of the three cigars ran into burn issues during the second third—albeit in different parts of the second third—but the draws were wonderful and there was no dearth of smoke at any point
I enjoyed the La Palina 1948 Diadema for the celebratory creation that it is
and would have no issues recommending it to someone who is looking for a medium-strength
I have worn many hats in my life up to this point: I started out as a photojournalist for the Dallas Morning News and the Fort Worth Star-Telegram
then transitioned to photographing weddings—both internationally and in the U.S.—for more than a decade
After realizing that there was a need for a cigar website containing better photographs and more in-depth information about each release
SmokingStogie quickly became one of the more influential cigar blogs on the internet
extremely hard-to-find and expensive cigars
and it was one of the predecessors to halfwheel
In a study led by Cornell microbiology professor Ian Hewson
scientists have discovered that a parasite is behind a severe die-off of long-spined sea urchins across the Caribbean Sea
which has had devastating consequences for coral reefs and surrounding marine ecosystems
Scientists have discovered that a parasite is behind a severe die-off of long-spined sea urchins across the Caribbean Sea
The long-spined sea urchins (Diadema antillarum) serve as vital herbivores that graze on algae
which if left unchecked will outcompete corals for resources and space and blanket them
the sea urchins are essential to maintaining coral health and balance in the marine ecosystem
Diadema mortalities were first reported in St
the condition was found across the Lesser Antilles
it had been detected in most of the Greater Antilles
Prior to an experiment designed to verify the source of infections
a healthy sea urchin was swabbed to ensure it had never been exposed to the ciliate parasite
Scientists have been trying to identify the cause of the mysterious illness
which has led to declines of between 85% and 95% compared to pre-mortality numbers in affected areas
they lose their spines and detach from their anchors
an international team of 42 scientists has identified the culprit as Philaster apodigitiformis
a unicellular eukaryote that is part of a group of 8,000 species called ciliates
apodigitiformis is a known parasite in fish
“Rarely are we afforded the opportunity to understand marine disease events in this detail, where we can actually work out a cause of it,” said marine ecologist Ian Hewson, professor of microbiology in the College of Agriculture and Life Sciences, and lead author of the study, “A Scuticociliate Causes Mass Mortality of Diadema antillarum in the Caribbean Sea,” which published online April 19 in Science Advances
Though scientists do not yet know how to treat P
discovering the parasite’s identity may help them design strategies for maintaining health in Diadema sea urchins that are being raised for restocking efforts across the region
“Knowing the pathogen's identity may also help mitigate risk to untouched Diadema through such things as boat traffic
or other ways it may be moved around,” he added
long-spined sea urchins were almost completely wiped out in the Caribbean by an unknown cause
leading to around 98% declines from previous numbers
but only by an estimated 12% from their pre-epidemic numbers
That die-off led to rapid degradation of many coral reefs across the region that persist today
with some coral species becoming extremely rare
The cause of the early 1980s outbreak was never determined
though Hewson and colleagues may now investigate whether P
apodigitiformis can be detected in Diadema museum samples from that time and region
the research team collected three types of Diadema samples
infected individuals; healthy individuals from the same site; and completely healthy individuals from an unaffected area
Rapid sample collection from 23 sites was made possible by the Atlantic and Gulf Rapid Reef Assessment program
a network that helped Hewson collaborate with scientists from the Van Hall Larenstein University of Applied Sciences in the Caribbean Netherlands
Collaborators prepared tissue samples and delivered them to Hewson’s lab at Cornell
a complicated process involving customs and border regulations
Hewson and colleagues then ran tests to identify viral or bacterial pathogens in the tissues using state-of-the-art molecular biological and veterinary pathological techniques
“They initially did not show any sort of unusual or candidate microorganisms at all,” Hewson said
It was then that Hewson decided to investigate genomic signals of eukaryotic microorganisms
I had an enormous signal of this scuticociliate Philaster,” Hewson said
He ran to the labs and pulled out fluid samples from Diadema that people in the field had collected
“That was the big ‘aha’ moment.” The ciliates were not present in samples from the control sites
apodigitiformis has been known to infect fish
this is the first time it has been associated with mass mortality in an invertebrate
Hewson, a faculty fellow at the Cornell Atkinson Center for Sustainability
a biological oceanographer at the University of South Florida
Petersburg Coastal and Marine Science Center in Florida
designed an experiment to test Koch’s Postulates – the gold standard test for proving beyond doubt that a microorganism is associated with a condition
Using fresh samples collected from infected Diadema from the Florida Keys and aquacultured Diadema (which had never been exposed to any pathogens) obtained from The Florida Aquarium’s Center for Conservation
the researchers infected the aquarium Diadema with ciliates isolated from the body fluid of infected Florida sea urchins
“Animals that were treated with the ciliate became sick and died in 60% of the cases,” Hewson said
They were then able to isolate and identify the very same P
apodigitiformis ciliate from those newly diseased animals
proving it was responsible for the disease
“Almost never are we able in a wildlife setting
to prove that a microorganism is actually responsible for disease,” Hewson said
Funders for the study include the National Science Foundation; the Cornell Atkinson Center for Sustainability; the National Oceanic and Atmospheric Administration; and the National Fish and Wildlife Foundation
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and its identity has been revealed by USGS and partners—providing a key piece of information for reef managers to begin planning mitigation strategies
This species of urchin experienced mass mortality from an unknown cause in the early 1980s
which decimated populations and led to shifts in coral reef community structure
The cause of this mass mortality was never established
but it ultimately contributed to the continued decline of coral reef ecosystems
antillarum populations began experiencing mass mortality in the Caribbean again with disease signs reminiscent of those seen nearly 40 years ago
occurring over 1-2 days from seemingly normal urchins to bare tests surrounded by a pile of spines
and Thierry Work of USGS were part of an international team that investigated the cause of this mass mortality event through combined molecular
and veterinary pathologic approaches to identify the pathogenic microbe
The team compared diseased and normal urchins from 23 sites across the Caribbean Sea and determined that a scuticociliate that is most similar to Philaster apodigitiformis is the organism responsible for the mass mortality of these urchins
While the team recognizes important gaps in knowledge of the pathogen’s environmental distribution
this is a critical first step to addressing this disease and helping managers develop effective disease mitigation strategies
USGS scientists are actively testing potential treatments on the ciliate in the lab
working to develop field deployable options that reef managers can use
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St. Petersburg Coastal and Marine Science Center News
Metrics details
Bindin is a sperm protein that mediates attachment and membrane fusion of gametes
The mode of bindin evolution varies across sea urchin genera studied to date
In three genera it evolves under positive selection
We studied bindin evolution in the pantropical sea urchin Diadema
which split from other studied genera 250 million years ago
We found that Diadema bindin is structurally similar to that of other genera
more slowly than in any other sea urchin genus
Only bindin of the recently rediscovered D
clarki shows evidence of positive selection
positive selection could arise from avoidance of maladaptive hybridization
yet their bindins show no evidence of positive selection
possibly because the two species spawn at different times
paucispinum also evolves slowly under purifying selection
one that leads to two presumed separate species that are formally still recognized as D
and another that includes all other species of the genus
mexicanum is a sister clade to this polytomy
We sequenced bindin genes from all the described and suspected species of the genus Diadema to examine the mode of evolution of this gene
We asked whether this protein evolves under positive selection
as it does in three other sea urchin genera
and whether patterns of sympatry and allopatry have affected the mode of bindin evolution of particular species
Consensus sequences of 2–3 clones per allele were constructed to reduce cloning errors
Additional clones were sequenced on an ad-hoc basis to eliminate suspected errors and ambiguities wherever necessary
Bindin from a single individual of the diadematid Echinothrix diadema collected at Isla del Coco
Costa Rica was sequenced by the same methods to serve as an outgroup
We obtained sequences of the first exon of bindin from all currently recognized or suspected species of Diadema
We also obtained full length bindin sequence from a subset of individuals of D
we were unable to amplify the full length bindin sequence of Diadema setosum or of D
palmeri; analyses including these two species are limited to the first exon
Sequences were submitted to GenBank under Accession Numbers MT365802-MT365868 and MT375187- MT375188
The Bayesian analysis was performed using a 4 × 4 DNA substitution model with equal variation across sites
A flat Dirichlet prior was used for the substitution model
with a beta distributed prior for the transition/transversion ratio
One quarter of the initial values were discarded as burnin
A maximum value of 0.01 in the standard deviation of the split frequencies was used as an indication that the chains had converged
using two rate classes and an optimized substitution model chosen by the Datamonkey Model Selection tool
three site classes are estimated for each branch
with the first class in each model constrained between 0 and 1
Model C requires one of the site classes to have ω fixed at 1
whereas model D allows all classes to vary freely
and (in the analysis of the first exon) the clades of the bindins of D
setosum were each allowed to vary individually
resulting in a model with five classes of ω
with the same set of background branches and only D
suggesting the presence of purifying selection
Such an excess of replacement over silent substitutions is indicative of strong positive selection
palmeri also showed a value of ω higher than 1 in the first exon (1.48)
We were not able to analyze the second exon of bindin in this species
In all other branches ω was considerably smaller than 1
indicating that selection was negative or that bindin evolved neutrally
amino acid site 367 changed from an Arginine (R) to a Glycine (G) and site 413 changed from Glycine (G) to Alanine (A)
Both of these sites changed again at more terminal branches
Amino acid site 347 changed from an Isoleucine (I) to a Valine (V) at the branch leading to the majority of the D
antillarum sequences but experienced at least one reversal at a terminal node containing a bindin sequence of D
a change from Proline (P) to Tyrosine (Y) at amino acid position 395
represents a change at a terminal node containing a sequence from D
suggesting that divergence in bindin is mostly a function of time
(albeit at a much lower rate than those of Pseudoboletia)
and this may explain the presence of shared bindin alleles in D
coupled with the recent splitting of these species
bindin in Diadema evolves slowly under purifying selection
with little adaptive divergence in all species except
selection on bindin would be relaxed if one of the earlier steps blocks interspecific fertilization before egg and sperm can come in intimate contact
Our knowledge of Diadema ecology and egg-sperm interactions is far from complete
but it does provide clues on some of the steps that could affect species recognition before bindin comes into play
spatial segregation of species of Diadema with overlapping geographical ranges is not likely to be an effective barrier to fertilization opportunities
The question of whether bindin is under selection in D
clarki because the reproductive cycle of this species overlaps with that of one of the other two species of Diadema
Or it may simply be that processes documented as acting on the bindin of Strongylocentrotus do not apply to other genera
Despite being a gamete recognition protein
the bindin of Diadema evolves slowly under purifying selection
like the bindin in four other sea urchin genera
All the genera in which fast bindin evolution has been found are members of the order Echinoida
Diadema joins Arbacia as a genus that does not belong to this order and also shows little evidence of selection on its bindin
whether evolution in bindin will be fast or slow does not appear to be phylogenetically determined
The reasons as to why bindin evolves fast in some genera and not in others remain obscure; however
has now been studied in nine genera in three orders of an entire class or organisms
The diversity of its modes of evolution may simply be a reflection of the extent of organismal diversity that has received attention
in contrast to other gamete recognition proteins
All data generated and analyzed for this study have been deposited in GenBank
Accession #s MT365802-MT365868 and MT375187-MT375188
Palumbi, S. R. Speciation and the evolution of gamete recognition genes: Pattern and process. Heredity 102, 66–76, https://doi.org/10.1038/hdy.2008.104 (2009)
Lessios, H. A. Speciation genes in free-spawning marine invertebrates. Integrative and Comparative Biology 51, 456–465, https://doi.org/10.1093/icb/icr039 (2011)
The rapid evolution of reproductive proteins
Vacquier, V. D. & Swanson, W. J. Selection in the rapid evolution of gamete recognition proteins in marine invertebrates. Cold Spring Harb Perspect Biol 3, a002931, https://doi.org/10.1101/cshperspect.a002931 (2011)
What have we learned about sea urchin sperm bindin
Development Growth & Differentiation 37
International Journal of Developmental Biology 52
Causes and consequences of the evolution of reproductive proteins
Sea urchin bindin divergence predicts gamete compatibility
In Rapidly Evolving Genes and Genetic Systems (eds R.S
Strong reproductive isolation between closely related tropical sea urchins (genus Echinometra)
Adaptive evolution of sperm bindin tracks egg incompatibility in neotropical sea urchins of the genus Echinometra
Positive selection and sequence rearrangements generate extensive polymorphism in the gamete recognition protein bindin
Reproductive character displacement and the genetics of gamete recognition in tropical sea urchins
The molecular evolution of sperm bindin in six species of sea urchins (Echinoida: Strongylocentrotidae)
Evaluation of sequence variation and selection in the bindin locus of the red sea urchin
Characterization of the sperm molecule bindin in the sea urchin genus Paracentrotus
Mitochondrial DNA and bindin gene sequence evolution among allopatric species of the sea urchin genus Arbacia
Phylogeography and bindin evolution in Arbacia
a sea urchin genus with an unusual distribution
Speciation on the coasts of the new world: Phylogeography and the evolution of bindin in the sea urchin genus
Natural hybridization in the sea urchin genus Pseudoboletia between species without apparent barriers to gamete recognition
Evolution of bindin in the pantropical sea urchin Tripneustes: comparisons to bindin of other genera
Adaptive evolution of bindin in the genus Heliocidaris is correlated with the shift to direct development
Low rates of bindin codon evolution in lecithotrophic Heliocidaris sea urchins
More than bindin divergence: reproductive isolation between sympatric subspecies of a sea urchin by asynchronous spawning
Reproductive isolation between species of sea urchins
Selection on gamete recognition proteins depends on sex
Sperm competition and the evolution of gametic compatibility in externally fertilizing taxa
The evolution of gametic compatibility and compatibility groups in the sea urchin Mesocentrotus franciscanus: An avenue for speciation in the sea
All males are not created equal: fertility differences depend on gamete recognition polymorphisms in sea urchins
Assortative mating drives linkage disequilibrium between sperm and egg recognition protein loci in the sea urchin Strongylocentrotus purpuratus
Population structure and speciation in tropical seas: global phylogeography of the sea urchin
A new species of Diadema (Echinodermata: Echinoidea: Diadematidae) from the eastern Atlantic Ocean and a neotype designation of Diadema antillarum Philippi
On the fourth Diadema species (Diadema-sp) from Japan
Unexpected discovery of Diadema clarki in the Coral Triangle
In Advances in Invertebrate Reproduction 5 (ed
Hybridization and introgression between Indo-Pacific species of Diadema
Kinetics of fertilization in the sea urchin Strongylocentrotus franciscanus: Interaction of gamete dilution
The aggregation behavior of Diadema (Echinodermata: Echinoidea)
Possible prezygotic reproductive isolation in sea urchins separated by the Isthmus of Panama
Population dynamics of Diadema antillarum (Echinodermata: Echinoidea) following mass mortality in Panama
Presence and absence of monthly reproductive rhythms among 8 Caribbean echinoids off the coast of Panama
Annual and lunar reproductive rhythms of the sea urchin Diadema antillarum (Philippi) in Bermuda
Preservation of avian blood and tissue samples for DNA analyses
Indo-Pacific echinoids in the tropical eastern Pacific
MAFFT online service: multiple sequence alignment
interactive sequence choice and visualization
Genetic algorithm approaches for the phylogenetic analysis of large biological sequence datasets under the maximum likelihood criterion
Thesis The University of Texas at Austin (2006)
MrBayes 3.2: Efficient Bayesian phylogenetic inference and model choice across a large model space
In Lectures on Mathematics in the Life Sciences Vol
Miura) 57-86 (American Mathematical Society (1986)
A simple method for estimating evolutionary rates of base substitutions through comparative studies of nucleotide sequences
MEGA7: molecular evolutionary genetics analysis version 7.0 for bigger datasets
Evolution of the Zfx and Zfy genes: rates and interdependence between the genes
Unbiased estimation of the rates of synonymous and nonsynonymous substitution
Simple methods for estimating the numbers of synonymous and nonsynonymous nucleotide substitutions
Automated phylogenetic detection of recombination using a genetic algorithm
Datamonkey 2010: a suite of phylogenetic analysis tools for evolutionary biology
Datamonkey: rapid detection of selective pressure on individual sites of codon alignments
PAML: a program package for phylogenetic analysis by maximum likelihood
PAML 4: phylogenetic analysis by maximum likelihood
Codon-substitution models for heterogeneous selection pressure at amino acid sites
The Neighbor-Joining method: a new method for reconstructing phylogenetic trees
Phylogenetic analyses using parsimony (*and other methods)
Accuracy and power of statistical methods for detecting adaptive evolution in protein coding sequences and for identifying positively selected sites
Bayes empirical Bayes inference of amino acid sites under positive selection
Pervasive adaptive evolution in mammalian fertilization proteins
A maximum likelihood method for detecting functional divergence at individual codon sites
An improved likelihood ratio test for detecting site-specific functional divergence among clades of protein-coding genes
Detecting individual sites subject to episodic diversifying selection
unconstrained Bayesian approximation for inferring selection
Instability of repetitive DNA sequences: the role of replication in multiple mechanisms
GT repeats are associated with recombination on human chromosome 22
Lack of character displacement in the male recognition molecule
in Altantic sea urchins of the genus Echinometra
A simple sequentially rejective multiple test procedure
Inferring phylogenies from mtDNA variation: mitochondrial-gene trees versus nuclear-gene trees
Predicting nuclear gene coalescence from mitochondrial data: The three-times rule
Coexistence in a sea-urchin guild and its implications to coral-reef diversity and degredation
Patterns of reproduction in four species of Indo-Pacific echinoderms
Neill, A. T. & Vacquier, V. D. Ligands and receptors mediating signal transduction in sea urchin spermatozoa. Reproduction 127, 141–149, https://doi.org/10.1530/rep.1.00085 (2004)
Evolution of gamete attraction molecules: evidence for purifying selection in speract and its receptor
Positive selection in the carbohydrate recognition domains of sea urchin sperm receptor for egg jelly (suREJ) proteins
Simultaneous positive and negative frequency-dependent selection on sperm bindin
a gamete recognition protein in the sea urchin Strongylocentrotus purpuratus
Contemporary evolution of sea urchin gamete-recognition proteins: Experimental evidence of density-dependant gamete performance predicts shifts in allele frequencies over time
Proceedings of the Royal Society B-Biological Sciences 268
Adaptation and phylogeny as determinants of egg size in echinoderms from the two sides of the isthmus of Panama
The importance of sperm limitation to the evolution of egg size in marine invertebrates
Membrane fusion is induced by a distinct peptide sequence of the sea urchin fertilization protein bindin
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This manuscript has been improved by the contributions of Santosh Jagadeeshan and two anonymous reviewers
Specimens for this study were contributed by W
Laboratoire de Biologie du Developpement de Villefranche-sur-mer (LBDV)
Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations
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DOI: https://doi.org/10.1038/s41598-020-66390-2
The Oliva Serie V has been made in just about every size and shape: normal sizes
a 9 x 52 diadema arrived in Holland and Germany
This was neither the first time Oliva used the 9 x 52 diadema mold
nor the first time the Serie V blend was offered in a diadema
It was limited to 400 boxes of 10 cigars with pricing set at €15 per cigar
It was during a period of a few consecutive years when Oliva made a special size for the European market
something that seems to have fallen out of favor lately
I reviewed the Serie V Diadema shortly before it came out and wasn’t overly impressed:
is simple: I’d rather buy and smoke two different cigars for the same money and time it would take me to smoke one of these monstrosities
While the Diademas are beautiful and are great to show off in a humidor
the size quickly becomes more annoying to smoke than anything else
this was a much different flavor profile for the Serie V
The classic smooth punch that allows Oliva’s long-standing flagship to be both full and easy is absent because the former falls short in the flavor category
nothing that makes you think richness; it’s just a mixture of above average smooth flavors with a decent amount of nicotine
While that and the easily acceptable construction might seem like enough
not compared to the other 10-plus vitolas of Serie V
*The release was described as between 300-400 boxes
I still remember getting my first Serie V Churchill Especials and being amazed at the great red clay color
and this cigar looks like just a large version of those
I love the subtle angles at the top and bottom of the massive cigar
but they sharpness of the angles make it far less round than a salomon
Aroma off the Ecuadorian wrapper has leather and Spanish cedar
The foot isn’t a ton more vibrant with similar flavors and some toasted nuts coming from the small hole at the bottom
Cold draw is a bit bizarre with a lot of herbal flavors joining the prominent Jalapa sweetness and spice that is so prominent on the Serie V
The gigantic Serie V starts with some roasted coffee and toasty notes
something I’m not too concerned with given the small opening at the bottom of the cigar
things change pretty quick and the first third is fairly vibrant with some white bread and burnt barbecue
Ninety minutes in and there’s an added floral flavor joining a roasted coffee
There’s a late charge of a big bubble gum flavor and lots of popcorn on the finish
sweet cedar and a basic Guinness stout flavor make up the last two inches
which is noticeably milder than the first seven inches
but it opens up once the nipple has been burned
There were two touch-ups throughout the three and a half hours worth of smoking
which is more than acceptable as far as I’m concerned given the length
more of a medium-full thud rather than a sharp punch
By the midway point I can detect it having some effect though it’s certainly a bit milder than I expected
The Oliva Serie V in non-Diadema form has been one of my favorite cigars
This is just a gigantic Serie V and after a few years
it seems clear I was missing the typical Serie V experience when these were fresh
This time the sweet and earthy mixture was more than present
as was the typical Serie V nicotine effect
it would be a tough choice between this and my go-to regular Serie V
as both provide the core Serie V flavors with a fair bit of complexity
That eight inch long one looks like a solid choice
That was my thought when I saw this pop up on the schedule
but then I remembered that I live in Phoenix
where winter lasts about three days and it will touch 70 degrees in January
the Tobacconists Association of America (TAA) is a group of approximately 80 prominent U.S
retailers that gets together for a meeting and trade show every spring
cigar manufacturers often bring some exclusive cigars for the retailers to sell
There are about 40 manufacturers who are also members of the TAA
At the 2018 meeting, which celebrated the TAA’s 50th anniversary, one of those manufacturers was CLE Cigar Co., which in 2015 celebrated the 20 years that company founder Christian Eiroa had spent in the cigar industry. That first celebratory cigar was a Honduran puro that came in three regular production sizes
there was one word that seemed to get a bit overlooked on the tissue paper that covered the cigar: series
In 2017, the line got its first extension, The First 20 Years Colorado
which used a Honduran corojo wrapper aged for five years over a Honduran binder and filler
Eiroa announced that he was creating a new cigar for the TAA
it would be sizable addition to the series
60 ring gauge at its fattest point and 48 at its most slender
though the wrapper comes from a Mexican seed that was grown at he Eiroa family’s Finca Corojo
The binder and the filler come from a unique seed called Victoria and that gets its name from the La Victoria farm that traces back to Generoso Eiroa
The Eiroa The First 20 Years Diadema offer lots to things that catch the eye
Two-thirds of the cigar is covered in a tissue paper with a smooth feel on the fingers and that is printed with the logo of the Eiroa The First 20 Years Series
Above that is a glossy red and gold band with some black trim
Once the tissue paper is removed—which requires tearing it somehow as it doesn’t slide off—the cigar looks even bigger
The paper covers up just how big the bulbed foot of the cigar is
which seems to command a ton of visual attention
The leaf is incredibly even in color with just a few small veins and a fine grit texture for the fingers
The wrapper offers an aroma of chocolate and coffee
though as a combination much like what I’d expect to smell from a stout that featured those two flavors as opposed to the source materials themselves
the small opening of the foot isn’t much help to develop that aroma
a cold draw reveals a somewhat surprisingly open draw
with flavors that aren’t as rich and thick as the aroma
I get more of a citrus syrup sweetness in the first sample while subtle earth and chocolate are most noticeable in the second
The final third is an interesting combination of the first two cigars
a bit of chocolate-covered mandarin oranges finished off by a bit of earthiness
I opt for a single flame torch lighter to just toast the foot of the nipple
largely in hopes of seeing how the burn line progresses but also because I don’t want to over toast the end of the cigar
and increases once the burn line hits the bulb of the foot
The flavor profile is lighter than I would have expected with a bit of chalk and metallic earth notes the first to stand out in the first sample
while the second has a sweet sausage character
The burn line could use a touchup as it starts moving up the cigar
something I’m not surprised about and wait as long as possible to actually break out the lighter
As the burn line passes the one-inch mark the ash continues to build
the profile gets a little more well-rounded by way of developing creaminess
though not appreciably fuller or more peppery
After building up two nearly two inches in length
the ash drops and the draw gets a touch looser
with the first sample now open enough to be slightly concerning
there’s a chocolate chip cookie note starting to emerge from the smoke
with black pepper coming along quickly behind that to turn the profile a bit rougher and jagged on the tongue
it backs off nearly as quickly in advance of the second third
settling in at medium bodied with a somewhat thin smoke texture
The final third starts on a bit lighter note than the fuller notes of the second third
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Metrics details
Reproductive success is the ultimate measure of individual quality; however
it is difficult to determine in free-living animals
indirect measures that are related to reproduction are generally employed
males typically possess longer tails than females and this sexual size dimorphism in tail length (TL) has generally been attributed to the importance of the tail in mating and reproduction
were hypothesized to reflect individual quality
We used a body condition index (BCI) as a measure of quality in snakes and predicted that tail length would be correlated with BCI in males
We tested our prediction by determining BCI in the free-ranging adult male and female crowned leafnose snake (Lytorhynchus diadema)
a colubrid species that inhabits mainly desert sand dunes
The relative TL was correlated positively and significantly to BCI in males (F1,131 = 11.05; r2adj = 0.07; P < 0.01) but not in females
This is the first time that the relationship between TL and body condition was tested in a free-ranging species
sexual size dimorphism of TL increased intra-specifically with body size
which was also found in interspecific analyses following Rensch’s rule
males with longer relative TL would be able to use more power over a short time for a successful mating and
we used BCI as a measure of individual quality
which we regarded as being related to reproductive success
A Lytorhynchus diadema at our research site in the Negev Desert
was significantly longer than that of females (n = 107)
the difference amounting to 4.5%; but the variance between sexes was similar (P = 0.348)
Sexual size dimorphism in SVL was 1.047 and the compressed index was −0.047
and the variance in TL in males was 72% higher than in females (0.62 vs 0.36; P < 0.01)
Tails of all males and females were intact
The effect of snout-vent length (SVL) on tail length in male (triangles; dashed line) and female (circles; solid line) Lytorhynchus diadema
The gap between the two regression lines represents the significant increase in sexual dimorphism of tail length with SVL; increase rate of tail length with SVL is higher in males than females (see text for explanation)
The effect of the residuals of tail length (TLr) on body condition index (BCI) in male (triangles; dashed line; the regression equation took the form of BCI = 1.01 TLr + 11.73; r2 = 0.07; P < 0.01; n = 133) and female (circles and solid line at mean BCI because of non-significant relationship; P = 0.17; n = 107) free-ranging Lytorhynchus diadema (see text for explanation)
A significant effect of resTL on BCI emerged in males but not in females; consequently
The higher variance of TL in males than in females provides further support to our hypothesis that the tail of male L
We questioned how could the non-significant effect for males in June be explained
diadema were exhausted and that may explain the non-significant effect of resTL on BCI in this month
males improved their body condition and in August
resTL explained 45% of the variance in BCI
this interpretation should be taken cautiously as BCI varies temporally and can change among years depending on environmental conditions
Body condition is an important parameter affecting both fecundity and fitness and is a measure of body energy reserves and
differentiates among individuals on the basis of their quality
we propose an intraspecific link between a specific characteristic and individual quality in free-ranging snakes
we were able to statistically explain much of the variance in TL and suggest consequences of individual quality
We conclude that the high TL dimorphism index in L
diadema reflects the importance of the male TL for successful mating
the male is the larger sex and the variance in TL was higher than that in the female
Our study design allowed testing whether evolutionary perspectives of Rensch’s rule can be applied intra-specifically as well as interspecifically for sexual dimorphism in TL
as SSD of TL between sexes increased with body size
It would be interesting to examine similar intraspecific relationships across various colubrid species and other taxa to test whether these findings reflect a general trend
M3) coiled around a female (F) at the entrance of a rodent burrow in a ‘mating ball’
diadema vary in color allowing the distinction among individuals
The dominant vegetation is of the Saharo-Arabian type with the main plants consisting of Artemisia monosperma
All procedures on the snakes were approved by the Israel Nature and National Parks Protection Authority and the Ben-Gurion University Committee for the Ethical Care and Use of Animals in Experiments
All methods were carried out in accordance with relevant guidelines and regulations
Neither surface water nor rainfall was available at the study site when the snakes were active
dehydration should not have been a factor in using BCI as a measure of body condition in this study
A t-test was used to test for differences in SVL
and the Levene test was used to test for differences in variance
To examine the effect of SSD of TL on SVL intra-specifically
an ANCOVA was used to test for difference between the two regression estimates of TL on SVL in males and females
Measurements are presented as means (±SE) and P < 0.05 was accepted as the level of significance
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Download references
We thank two anonymous reviewers and Ido Tsurim for helpful suggestions
Tracking of animals and experimental procedures were done with permission from the Israel Nature and National Parks Protection Authority
All authors conceived and designed the experiments; J.S.
analyzed the data and wrote the manuscript
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DOI: https://doi.org/10.1038/s41598-020-61168-y
will conduct fieldwork in Key Largo/Tavernier, Florida Keys
visiting sentinel sites that experienced mass mortality events of Diadema antillarum in 2022 to determine if the causative parasite can still be detected.
Kellogg will screen large volumes of water
and swabs from fishes for the presence of the scuticociliate DaScPc (Diadema antillarum Scuticociliatosis Philaster clade). Diadema antillarum
This species of urchin experienced mass mortality from an unknown cause in the early 1980s, and again in 2022 from a scuticociliate
The scuticociliate has spread to the Mediterranean
Determining whether the parasite is still present in the Keys after 2 years is important for reef managers who are conducting coral restoration and want to include hatchery-raised Diadema as part of their strategy
SPCMSC Research Marine Biologist James Evans
and Research Microbiologist Christina Kellogg
The parasite that was identified as the cause of Diadema antillarum sea urchin mass mortality in the Caribbean in 2022 has been shown to be the cause of a die off in the Sea of Oman
affecting sibling-species Diadema setosum.
Researchers in Oman reported a mass mortality of D
and reached out to collaborate to find the cause
Infected environmental samples were confirmed by genomic tests to contain the same ciliate parasite that killed D
setosum obtained from the aquarium trade were challenged with the ciliate in a controlled experiment and demonstrated to be susceptible to the ciliate
This work was conducted at the University of South Florida and included USGS scientists Christina Kellogg and James Evans
Read the article: "Transglobal spread of an ecologically relevant sea urchin parasite"
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