Holothurian Species Research Articles

Holothurian fucosylated chondroitin sulfate.

Fucosylated chondroitin sulfate (FucCS) is a structurally distinct glycosaminoglycan found in sea cucumber species. It has the same backbone composition of alternating 4-linked glucuronic acid and 3-linked N-acetyl galactosamine residues within disaccharide repeating units as regularly found in mammalian chondroitin sulfates. However, FucCS has also sulfated fucosyl branching units 3-O-linked to the acid residues. The sulfation patterns of these branches vary accordingly with holothurian species and account for different biological actions and responses. FucCSs may exhibit anticoagulant, antithrombotic, anti-inflammatory, anticancer, antiviral, and pro-angiogenic activities, besides its beneficial effects in hemodialysis, cellular growth modulation, fibrosis and hyperglycemia. Through an historical overview, this document covers most of the science regarding the holothurian FucCS. Both structural and medical properties of this unique GAG, investigated during the last 25 years, are systematically discussed herein.

Sea Cucumber: New source of Protein for Human Consumption

Event Abstract Back to Event Sea Cucumber: New source of Protein for Human Consumption Daniela V. Pratas1*, Filipa P. Santos1, Teresa Baptista1 and Ana Violante Pombo1 1 GIRM , Marine Resources Research Group, IPL, Portugal Aquaculture, probably the fastest growing food-producing sector, now accounts for nearly 50 percent of the world's food fish consumed by humans, and this share is expected to increase further to meet future demand. Sea cucumbers are considered highly marketable product and this has resulted in an increasing overfishing of natural sea cucumber stocks. Nevertheless, these resources are almost unexploited in the Mediterranean region. Many species of holothurians have been recognized as an alternative source of first quality protein and considered a putative functional food, like hypocholesterolemic proprieties and contain many other bioactive compounds. Therefore, the aim of the present study was to determine and compare the protein content of two sea cucumber species, Holothuria forskali and Stichopus regalis. The Kjeldahl method was used to determine the crude protein through the measurement of nitrogen amount in each sample. The obtained results demonstrated that both species contain high protein levels, with higher results for S. regalis, which revealed values between 19,1% and 20,4%. H. forskali showed a protein level among 12,1% and 15,4%. Holothurian protein levels reveal great potential for human consumption. Those resources can be used as a partial substitute of fish meal (eg. sea bream nutrition), either to intern market as well as for exportation to Asian countries. Sea cucumber farming could have lucrative potential in the Mediterranean, converting sea cucumbers into aquaculture value-added products bringing to this region profitable economic benefits. Keywords: holothurian, sea cucumber, protein, Aquaculture, Mediterranean Conference: IMMR | International Meeting on Marine Research 2014, Peniche, Portugal, 10 Jul - 11 Jul, 2014. Presentation Type: Poster Presentation Topic: AQUACULTURE Citation: Pratas DV, Santos FP, Baptista T and Violante Pombo A (2014). Sea Cucumber: New source of Protein for Human Consumption. Front. Mar. Sci. Conference Abstract: IMMR | International Meeting on Marine Research 2014. doi: 10.3389/conf.fmars.2014.02.00124 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 25 Apr 2014; Published Online: 18 Jul 2014. * Correspondence: Dr. Daniela V Pratas, GIRM , Marine Resources Research Group, IPL, Peniche, Portugal, 4130347@my.ipleiria.pt Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Daniela V Pratas Filipa P Santos Teresa Baptista Ana Violante Pombo Google Daniela V Pratas Filipa P Santos Teresa Baptista Ana Violante Pombo Google Scholar Daniela V Pratas Filipa P Santos Teresa Baptista Ana Violante Pombo PubMed Daniela V Pratas Filipa P Santos Teresa Baptista Ana Violante Pombo Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

Asexual reproduction in holothurians.

Aspects of asexual reproduction in holothurians are discussed. Holothurians are significant as fishery and aquaculture items and have high commercial value. The last review on holothurian asexual reproduction was published 18 years ago and included only 8 species. An analysis of the available literature shows that asexual reproduction has now been confirmed in 16 holothurian species. Five additional species are also most likely capable of fission. The recent discovery of new fissiparous holothurian species indicates that this reproduction mode is more widespread in Holothuroidea than previously believed. New data about the history of the discovery of asexual reproduction in holothurians, features of fission, and regeneration of anterior and posterior fragments are described here. Asexual reproduction is obviously controlled by the integrated systems of the organism, primarily the nervous system. Special molecular mechanisms appear to determine the location where fission occurs along the anterior-posterior axis of the body. Alteration of the connective tissue strength of the body wall may play an important role during fission of holothurians. The basic mechanism of fission is the interaction of matrix metalloproteinases, their inhibitors, and enzymes forming cross-link complexes between fibrils of collagen. The population dynamics of fissiparous holothurians are discussed.

On the reproduction of the simultaneous hermaphrodite Paroriza prouhoi (Holothuroidea: Synallactidae) in the Porcupine Abyssal Plain, north-east Atlantic

Long-term studies in the abyssal north-east Atlantic (1989–2005) have revealed large-scale changes in the benthic ecosystem and especially in some megafaunal invertebrate taxa over the period 1996–2002, termed the ‘Amperima Event’. Holothurians dominated the megafaunal samples. Temporal patterns in the abundance of holothurians showed a wide spectrum of responses, possibly related to the feeding and reproductive characteristics of the various species. One of the holothurians, the synallactid Paroriza prouhoi, is a simultaneous hermaphrodite, providing a distinct comparison with dioecious reproductive patterns more typical of deep-sea holothurian species. The reproductive biology and abundance/biomass patterns of P. prouhoi were investigated over the period 1989–2005. Paroriza prouhoi produces oocytes with a maximum diameter of ~370 µm. It has asynchronous patterns of gametogenesis both at the individual and population levels. Mean oocyte diameter and the ratio between previtellogenic and vitellogenic oocytes showed no significant differences between the periods prior to and after the Amperima Event. There were no significant differences in abundance or biomass over the time series. We conclude that the energy investment into gamete production by this hermaphrodite did not change over the 16 years examined. It is hypothesized that the feeding characteristics of P. prouhoi lead to a slow, steady and consistent production of gametes despite large-scale changes in organic matter supply to the seabed evident at the time series locality.

Bacterial diversity of the sediments transiting through the gut of Holothuria scabra (Holothuroidea; Echinodermata)

This work analyzes bacterial diversity of sediments transiting through the gut of Holothuria scabra which is an important bioturbator in tropical shallow waters. This edible holothurian species has a social and economic importance for coastal populations in many developing countries. Bacterial biodiversity was analyzed by sequencing the 16S rRNA of bacterial cultures and clones. DAPI and FISH methods were used to determine and compare the number of bacteria found in the various gut compartments. A total of 116 phylotypes belonging to the γ-Proteobacteria (60.5 %), α-Proteobacteria (24.5 %), Bacteroidetes (6 %), Actinobacteria (2.75 %), Fusobacteria (1.75 %), Firmicutes (1.75 %), Cyanobacteria (1.75 %) and δ-Proteobacteria (1 %) were identified. The number of bacteria is significantly greater (1.5×) in the foregut than in the ambient sediments. The number of bacteria significantly decreases in the midgut and remains stable until defecation. Some γ-Proteobacteria, especially Vibrio, are less affected by digestion than other bacterial taxa. The season has an impact on the bacterial diversity found in the sediments transiting through the gut: in the dry season, γ-Proteobacteria are the most abundant taxon, while α-Proteobacteria dominate in the rainy season. Vibrio is the most frequent genus with some well-known opportunistic pathogens like V. harveyi, V. alginolyticus and V. proteolyticus. Findings show that sediment-associated microbial communities are significantly modified by H. scabra during their transit through the gut which supports the view that holothurians play a substantial role in the structuring of bacterial communities at the sediment–seawater interface.

Reproductive biology of Holothuria fuscocinerea (Echinodermata: Holothuroidea) from Oaxaca, Mexico

The sea cucumber Holothuria fuscocinerea is among the most common holothurian species widely distributed in the Tropical Eastern Pacific Region and is becoming a potentially important fishery in Mexico. Nevertheless, there are no studies about its reproductive biology. This study analyzed several reproductive traits of H. fuscocinerea based on monthly time-series samples taken from April 2008 to March 2009 at La Entrega Bay, Oaxaca, in the Mexican tropical Pacific. Sex ratio, gonad development stages (GDS), reproductive cycle, diameter and distribution of oocytes, and fecundity were determined. Reproductive indices (the gonadosomatic index (GSI) and maturity index (MI)) were calculated, and their relationship with some environmental factors (temperature, rainfall, salinity, and pH) was evaluated. H. fuscocinerea is a gonochoric holo - thuroid, and its annual ratio of males to females was not significantly different from 1:1. Four GDS (i.e. gametogenesis, mature, spawning, post-spawning) as well as one period of gonadal recovery, which is 'sexually undifferentiated', were established. Spawning occurred from June to October in females and from April to September in males. Post-spawning of females and males and recov- ery stages coincided from October to January. Mean fecundity was 2.9 ± 2.8 million oocytes per female, with ovaries exclusively comprised of vitellogenic oocytes from June to September. GSI and MI values showed similar variations in accordance with the reproductive cycle, and GSI showed a relationship with rainfall season. Seasonal rainfall may act as a cause of the seasonal reproductive pattern observed in H. fuscocinerea.

Holothuroidea of the Charlie Gibbs Fracture Zone area, northern Mid-Atlantic Ridge

Holothurians are among the most species-rich taxa in the megabenthos on the northern Mid-Atlantic Ridge at depths of 2200–3700 m. Extensive new collections of 32 holothurian species were made in 2007–2010 in the Charlie Gibbs Fracture Zone area as part of the ECOMAR project. New material includes samples taken using a trawl and the ROV Isis. Samples and in situ observations from the ROV were of particular value because the morphological details of a number of holothurian species could be clarified. Many of these species are gelatinous and fragile and were damaged in trawls. Three species of elasipodid holothurians are described as new to science. An annotated check-list of all species of deep-sea holothurians collected in the Charlie Gibbs Fracture Zone area is provided. The checklist includes synonyms, distribution data and morphological descriptions as well as photographs taken in situ and in vivo. Ecological remarks are given for some species.

Proteolysis of noncollagenous proteins in sea cucumber, Stichopus japonicus, body wall: Characterisation and the effects of cysteine protease inhibitors

Proteolysis of noncollagenous proteins in sea cucumber, Stichopus Japonicus, body wall (sjBW) was investigated. The proteins removed from sjBW by SDS and urea extraction were mainly noncollagenous proteins with molecular weights about 200kDa (Band I) and 44kDa (Band II), respectively. Band I and Band II were identified as major yolk protein (MYP) and actin, respectively, from holothurian species by liquid chromatography–mass spectrometry (LC–MS/MS) with significant scores. Based on TCA-soluble oligopeptide assay, the optimum proteolysis condition of noncollagenous proteins was at 46.3°C and pH 6.1, by response surface methodology. The proteolysis of MYP, and actin, was partially inhibited by cysteine protease inhibitors, including Trans-epoxysuccinyl-l-leucyl-amido (4-guanidino) butane (E-64), iodoacetic acid, antipain and whey protein concentrate. These results suggest that cysteine proteases are partially involved in the proteolysis of noncollagenous proteins in body wall of sea cucumber, S. japonicus.

Inter-annual dynamics of abyssal polychaete communities in the North East Pacific and North East Atlantic—A family-level study

Characterising how deep-sea communities change on contemporary time-scales and understanding underlying ecosystem processes has become important under changing climate and the rise in the exploitation of deep-sea resources. However, little is known about these dynamics and processes. Long-term observations from which inter-annual variations can be detected are scarce in the deep sea. This study examines inter-annual changes in density, family richness and evenness, family and functional group rank abundance distributions of infaunal polychaetes at two abyssal stations in the North East Pacific (Station M, 1991 to 2005) and in the North East Atlantic (Porcupine Abyssal Plain, 1991 to 1999). The two long-term data sets were used to investigate not only if polychaete community structure and composition varied at inter-annual scales in terms of diversity and rank abundance distributions but also if any changes were related to previous observations in megafauna and environmental factors at each locality. The polychaete community structure at each locality was analysed using univariate statistics as well as multivariate ordination techniques based on Bray-Curtis similarity of the yearly family density. Sub-surface deposit feeders, such as Paraonidae, dominated the North East Pacific, whereas surface deposit feeders, such as Cirratulidae, dominated the North East Atlantic. Both stations showed inter-annual variations in density, family evenness and rank abundance distributions. The greatest changes occurred in 1998 in both time series when polychaete densities peaked, and switches in the rank abundance of the most abundant families and functional groups took place. Inter-annual variations in the polychaete community were correlated with a limited number of holothurian species changes, but no correlation was found with particulate organic matter flux or climate indices. Ecological and environmental factors behind the family-level changes remain elusive. Overall, changes in the dominance of functional groups imply changes in abyssal ecosystem functioning with potential consequences on carbon cycling at the seabed.

<p><strong>Swimming deep-sea holothurians (Echinodermata: Holothuroidea) on the northern Mid-Atlantic Ridge*</strong></p>

The ability to swim was recorded in 17 of 32 species of deep-sea holothurians during the RRS James Cook ECOMAR cruise in 2010 to the Mid-Atlantic Ridge. Holothurians were observed, photographed, and video recorded using the ROV Isis at four sites around the Charlie-Gibbs Fracture Zone at approximate depths of 2,200–2,800 m. For eleven species swimming is reported for the first time. A number of swimming species were observed on rocks, cliffs and steep slopes with taluses. These habitats are unusual for deep-sea holothurians, which are traditionally common on flat areas with soft sediment rich in detritus. Three species were found exclusively on cliffs. Swimming may provide an advantage in cliff habitats that are inaccessible to most epibenthic deposit-feeders.

Asexual reproduction, evisceration, and regeneration in holothurians (Holothuroidea) from Nha Trang Bay of the South China Sea

Peculiarities of asexual reproduction, evisceration, and regeneration were studied in 13 holothurian species of the orders Dendrochirotida and Aspidochirotida from Nha Trang Bay of the South China Sea. Asexual reproduction by fission has been described for the first time for Cladolabes schmeltzii. It has been shown for the first time that transected C. schmeltzii and Colochirus robustus successfully regenerate not only their anterior, but also their posterior structures. It was found that Pseudocolochirus violaceus was able to regenerate the anterior part of the body and to eject viscera through the anus. The modes of evisceration and regeneration of the gut have been elucidated for ten species of aspidochirotids. It has been shown that the intestine of Holothuria scabra forms from two anlagen rather than from a single one, as previously believed.

Abstracts of the 17th International Symposium on Bioluminescence and Chemiluminescence ‐ (ISBC 2012)

WARNING : The light-emitting molecular structures responsible for the chemiluminescence and fluorescence phenomena are not necessarily the same!

Isolation and characterisation of eighteen microsatellite markers from the sea cucumber Holothuria scabra (Echinodermata : Holothuriidae)

We isolated 18 new, polymorphic, microsatellite markers from Holothuria scabra, a commercially important species of sea cucumber found throughout the Asia-Pacific region. Next-generation sequencing was used to identify 206 unique loci for which primers were designed. Of these unique loci, we trialled 65 primer pairs in the target species, and 48 (74%) amplified a product of the expected size. Eighteen loci were found to be polymorphic and reliable, and were screened for variation in 50 individuals, from a single population from Croker Island, Northern Territory, Australia. Observed heterozygosity ranged from 0.00 to 0.96 (mean = 0.46) and the number of alleles per locus from 2 to 28 (mean = 9.61). These loci will be useful for the investigation of population structure and mating systems in H. scabra and may also be of use in other holothurian species.

Microbial Communities Associated with Holothurians: Presence of Unique Bacteria in the Coelomic Fluid

Marine invertebrates interact with various microorganisms ranging from pathogens to symbionts. One-to-one symbiosis between a single microbial species and a single host animal has served as a model for the study of host-microbe interactions. In addition, increasing attention has recently been focused on the complex symbiotic associations, e.g., associations between sponges and their symbionts, due to their biotechnological potential; however, relatively little is known about the microbial diversity associated with members of the phylum Echinodermata. Here, for the first time, we investigated microbial communities associated with a commercially important holothurian species, Apostichopus japonicus, using culture-dependent and -independent methods. Diverse and abundant heterotrophs, mostly Gammaproteobacteria members, were cultured semi-quantitatively. Using the cloning and sequencing technique, different microbial communities were found in different holothurian tissues. In the holothurian coelomic fluid, potentially metabolically active and phylogenetically unique members of Epsilonproteobacteria and Rickettsiales were discovered. This study suggests that coelomic fluids of marine invertebrates, at least those inhabiting intertidal areas where physical and chemical conditions fluctuate, provide microbes with unique and stable habitats.

Modelling habitat associations of 14 species of holothurians from an unfished coral atoll: implications for fisheries management

AB Aquatic Biology Contact the journal Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections AB 14:57-66 (2011) - DOI: https://doi.org/10.3354/ab00381 Modelling habitat associations of 14 species of holothurians from an unfished coral atoll: implications for fisheries management L. M. Bellchambers1,*, J. J. Meeuwig2, S. N. Evans1, P. Legendre2,3 1Department of Fisheries, Western Australian Fisheries and Marine Research Laboratories, North Beach, Western Australia 6920, Australia 2The University of Western Australia, School of Animal Biology and Centre for Marine Futures, Oceans Institute, Crawley, Western Australia 6009, Australia 3Université de Montréal, Département de Sciences Biologiques, Montréal, Québec H3C 3J7, Canada *Email: lynda.bellchambers@fish.wa.gov.au ABSTRACT: Currently there is no commercial or subsistence fishing for holothurians on the Cocos (Keeling) Islands and, despite a prominent government presence, no reported cases of poaching or illegal fishing. However, because of recent interest in developing a commercial fishery for holothurians there, a survey was initiated to provide baseline data on the previously unfished local holothurian populations. Fourteen species of holothurians were recorded during the survey, with the most abundant species being Holothuria atra; only 4 other species had relatively high abundances. A total of 20556 holothurians were counted; however, 97% of these were considered to be of low commercial value. The high- and medium-value species found in this survey were all in extremely low abundances, with restricted distributions. The distribution and abundance of holothurians was closely linked with benthic habitats, with 48% of the variation in holothurian populations explained by 13 habitat variables. Several species displayed distinct habitat preferences: H. atra was associated with sand-dominated habitats, Actinopyga mauritiana was associated with relic reefs and soft corals, while Holothuria fuscopunctata and Stichopus herrmanni were both associated with reef flats. The densities recorded in the present study represent the natural abundance and distribution of holothurian populations at this atoll. Given the low numbers of commercially important species, it is highly unlikely that a commercial fishery would be economically viable at the Cocos (Keeling) Islands and it would be more beneficial to maintain the natural holothurian population. KEY WORDS: Holothurians · Habitat associations · Coral reefs · Exploitation · Unfished populations Full text in pdf format PreviousNextCite this article as: Bellchambers LM, Meeuwig JJ, Evans SN, Legendre P (2011) Modelling habitat associations of 14 species of holothurians from an unfished coral atoll: implications for fisheries management. Aquat Biol 14:57-66. https://doi.org/10.3354/ab00381 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in AB Vol. 14, No. 1. Online publication date: December 06, 2011 Print ISSN: 1864-7782; Online ISSN: 1864-7790 Copyright © 2011 Inter-Research.

The significance of habitat and exposure to the reef-flat macroinvertebrates of Rarotonga, Cook Islands, for conservation planning

Marine habitats are often used as surrogates of biodiversity for marine park planning. In this study we investigate the significance of both habitat and wind exposure to reef-top macroinvertebrates to determine whether habitats alone provide a surrogate of biodiversity. Detailed habitat maps of the reef flat of Rarotonga (Cook Islands) and historical wind data, were used to assess the distribution and abundance of the macroinvertebrate fauna of the reef-top. Macroinvertebrates were surveyed along transects at 128 sites in four main, broad habitat types (rubble/rock, sand/ coral, sand and algal rim) and two exposure categories (windward/leeward). Analyses of variance on the most abundant species and multivariate ordination (nMDS) found that habitat was more important than exposure per se in explaining the abundance of species and the composition of assemblages. The rubble/rock habitat had the greatest substratum heterogeneity and structural complexity and supported the largest number of species and individuals. Five of the abundant holothurian species and two echinoids (Echinometra mathaei and Tripneustes gratilla) were most abundant in the rubble/rock, while two holothurian species (Holothuria cinerascens and Actinopyga mauritiana) and the gastropod Trochus niloticus, were most abundant in the algal rim. Spatial data for the five most abundant species and two of the key fisheries species highlighted the significance of the south-eastern, windward coast to all species, an area that is most likely to be impacted by an increase in the frequency and magnitude of major storm events under future climate change scenarios.

Population trends of remote invertebrate resources in a marine reserve: trochus and holothurians at Ashmore Reef.

Marine protected areas (MPAs) have a high capacity to protect fish and invertebrate resources, given adequate surveillance and enforcement. Ashmore Reef National Nature Reserve (Ashmore Reef) was closed to commercial fishing and harvesting of invertebrates such as trochus (Trochus niloticus) and holothurians in 1983. We evaluate population trends in trochus and holothurians during eight years of monitoring, focusing largely on the differences between their populations before and after a lapse of surveillance. The trochus population increased in density from 1998 to 2005, followed by a slight decline in all surveyed habitats in 2006. This decline followed approximately five consecutive months without surveillance. Amongst populations of 18 species of holothurians, densities declined in five, and remained relatively stable in the others. Densities of commercially valuable holothurians (primarily Holothuria whitmaei and H. fuscogilva) were too low to allow the detection of trends. Continuous enforcement of the fishing closure is important to ensure successful conservation of Ashmore Reef, as are standardized monitoring techniques to enable temporal trends to be detected with confidence.

Reproductive Biology of Actinopyga echinites and Other Sea Cucumbers from La Réunion (Western Indian Ocean): Implications for Fishery Management

—The sea cucumber fishery is important in several countries of the Western Indian Ocean (WIO) but is generally not adequately managed. A regional MASMA programme (Marine Science for Management) granted by WIOMSA (Western Indian Ocean Marine Sciences Association) is providing data on the reproduction of some commercial species. In La Réunion, the two target species are Actinopyga echinites and Holothuria leucospilota. These sea cucumbers are very abundant on the fringing reefs and were sampled monthly during 2005-2006. Data on the population structure and on the reproductive cycle of A. echinites are presented here. The main results are: 1) eviscerated weight (EW) distribution of individuals within the population of Planch’Alizés site is plurimodal with a main mode at 85-95g, 2) sex-ratio is skewed toward females, 3) anatomy of gonads is described in five maturity stages, 4) a seasonal reproductive cycle with a major spawning event in December-January and a minor spawning event in April, 5) size at first sexual maturity EW50 equal to 45g is determined from another site (a sea grass bed with juveniles). These results are integrated with data from other holothurian species such as H. leucospilota, H. atra and Stichopus chloronotus previously studied in La Réunion and will be useful for research on the reproductive biology of sea cucumbers conducted in the other countries of WIO. ‘Seasonal closure’ using resultson the spawning season during the warm waters period and ‘minimum size’ using size at first sexual maturity are tools for enhancing sustainable management of the fisheries.Keywords: Sea cucumber, Actinopyga echinites, Aspidochirotid holothurians, reproductive season, first sexual maturity, fishery management, La Réunion, Western Indian Ocean

Genetic barcoding of commercial Bêche‐de‐mer species (Echinodermata: Holothuroidea)

There are more than 47 species of holothurians used for bêche-de-mer production, many of which are locally overfished. With three exceptions, all bêche-de-mer species are Aspidochirotida and species identification of many of these is difficult. We analysed available genetic information and newly generated sequences to determine if genetic barcoding with the mitochondrial COI gene can be used to identify bêche-de-mer species. Although genetic data were available for ∼50% of bêche-de-mer species, sufficient information and within-species replication were only available for six species. We generated 96 new COI sequences extending the existing database to cover most common species. COI unambiguously identified most bêche-de-mer species providing a genetic barcode for the identification of known species. In addition, conspecific (1.3%) variation and congeneric (16.9%) divergence were well separated ('barcoding-gap') albeit with a small overlap, which may lead to some error if genetic sampling alone was applied for species discovery. In addition to identification of adults, COI sequences were useful to identify juveniles that are often morphologically different. Sequence data showed that large (deep) and small (shallow) morphotypes of Holothuria atra are the same species, but suggested potential cryptic species within this taxon. For bêche-de-mer, the COI barcode proved useful in species clarification and discovery, but further genetic and taxonomic work is essential for several species. Some bêche-de-mer clades were problematic with morphologically disparate specimens sharing the same barcode. Our study indicated the presence of undescribed species (Bohadschia sp.) and species that constitute separate species in the Indian and Pacific Ocean (e.g. Holothuria fuscogilva).

A taxonomic guide to the Echinodermata of the South Atlantic Bight, USA: 1. Sea cucumbers (Echinodermata: Holothuroidea)

A summary account is given of the 33 holothurian species known from the South Atlantic Bight, from Cape Hatteras, North Carolina, to Cape Canaveral, Florida, from the shore to a depth of 200 meters. Four of the six known orders of holothurians are represented in the study area. Each species is diagnosed and illustrated; citations of informative literature and brief discussions of distribution and general biology are included. Also included are dichotomous keys to aid in identification to the species level. A new genus is erected to accommodate Pseudocolochirus mysticus Deichmann, 1930. Ocnus pygmaeus (Théel, 1886b) and O. surinamensis (Semper, 1868) are referred to the genus Aslia Rowe, 1970.