Holothuria Scabra Research Articles

Sea Cucumber Aquaculture in the Western Indian Ocean: Challenges for Sustainable Livelihood and Stock Improvement

The decline in sea cucumber fisheries that serve the Asian dried seafood market has prompted an increase in global sea cucumber aquaculture. The tropical sandfish (Holothuria scabra) has, in this context, been reared and produced with mixed success. In the Western Indian Ocean, villagers often participate in the export fishery for sea cucumbers as a source of income. However, with a growing concern of depleted stocks introduction of hatcheries to farm sandfish as a community livelihood and to replenish wild stocks is being promoted. This review identifies and discusses a number of aspects that constitute constraints or implications with regard to development of sandfish farming in the region. The conclusion is that for sandfish farming to live up to its expectations the possible impacts need to be further studied, and that improved evaluation of ongoing projects is required. In the interim, a precautionary approach toward new enterprise activities is suggested.

PEMBERIAN TOTAL FENOL TERIPANG PASIR (Holothuria scabra) UNTUK MENINGKATKAN LEUKOSIT DAN DIFERENSIAL LEUKOSIT IKAN MAS (Cyprinus carpio) YANG DIINFEKSI BAKTERI Aeromonas Hydrophila

Freshwater fishery commodities are most likely to be increased production of carp (Cyprinus carpio). Intensification of cultivation which raises new problems with fish disease outbreaks caused by Aeromonas hydrophila. Providing of immunostimulatory bioactive compounds of sea cucumbers (Holothuria scabra) can enhance non-specific immune responses in the goldfish as a mechanism of defense against disease. The purpose of this study is to determine the role and optimal dose of total phenols sea cucumber in enhancing non-specific immune response seen from the hematology parameters Extraction of bioactive components from sea cucumber prepared by using methanol and fractionated with ethyl acetate solvent (v/v). Identification of total phenols in ethyl acetate fraction performed using UV-Vis spectrophotometer and infrared. Total phenol produced was tested on carp with intraperitonial injection, the concentration of 0.09, 0.18 and 0.27 mg phenol/kg fish. Challenge test was done by using the Aeromonas hydrophila (10 7 cells/ml) through the immersion method. The observations included hematological parameters and total plasma proteins.The observations of hematological parameters that Leukocytes, Neutrophils pre-and post-infection were significantly increased. Lymphocyte pre infection was increased significantly and post-bacterial infection was decreased significantly. Eosinophils, Monocytes pre-and post-bacterial infection were not differ significantly between treatment. The use of phenolic compounds at 0.09 mg / kg can be increase of non-specific immune response in carp (Cyprinus carpio). Key Words : Total phenol, Aeromonas hydrophila, Cyprinus carpio, nonspecific immune response

Size measurement and nutritional condition evaluation methods in sandfish (Holothuria scabra Jaeger)

The aims of this study were to establish an accurate size measurement method and a nutritional condition evaluation method of Holothuria scabra (Jaeger). Although 0.5% KCl and 0.05% MgSO4 did not induce anaesthesia, 2% menthol–ethanol for 20 min was found to be effective and harmless. The anaesthetization significantly reduced the coefficient of variation of the mean body length and weight by 68% and 43% respectively. During starvation, body size and weight decreased concomitantly, resulting in an unchanged condition factor (body weight/volume), suggesting that the condition factor cannot be used as an index of nutritional condition. Protein, cholesterol and carbohydrate concentrations in the body fluid were analysed to study the relationship with starvation. As the protein and cholesterol concentrations initially increased and then decreased during the starvation period, it is difficult to use them as an index of nutritional condition. The carbohydrate concentration showed a gradual one‐fold increase during 10 days of starvation, and it may be used as a proxy for nutritional condition; however, further physiological studies are needed. Body fluid density and volume relative to body size gradually increased and decreased, respectively, during starvation. These methods may be used to correctly monitor the conditions of H. scabra in studies for aquaculture and stock enhancement techniques.

Parameter Optimization in the Extraction of Sea Cucumber (<i>Holothuria scabra j</i>) as a Source of Testosterone

Testosterone, the steroid hormone used in sex reversal and as an aphrodisiac, is produced not only by sea cucumber, but many other organisms too. This research was aimed at optimizing conventional extraction of testosterone from sea cucumber, looking at method, type of solvent, solvent ratio, and temperature for isolation. The results showed that extraction by reflux produced the highest testosterone content, followed by soxhlet extraction. The lowest yield was produced by maceration extraction. The solvents selected were acetone, methanol, methanol/chloroform mixture (1:2) and chloroform. The highest result was obtained by methanol/chloroform (0.2728 mg /100g dry weight (dw)), followed by acetone (0.2623 mg), chloroform (0.1606 mg) and methanol (0.0920 mg). Ratios of material:solvent used were 1:1, 1:2 and 1:3 respectively. Results improved as the amount of solvent was increased, so a ratio of 1:3 was most successful and 1:1 least successful. The effects of temperature and time on scale-up reflux extraction were also studied. Scale-up reflux extraction of 3000 ml showed that raising the temperature increases the percentage of sea cucumber extract.

Primary test on artificial spawning induction and larvae rearing of Holothuria scabra

Holothuria scabra is an important tropical sea cucumber species in South China.Combining methods of thermal stimulation,dry treatment and powerful water jet,etc.,we artificially induced the spawning and successfully bred H.scabra for the first time in China.During April~June,2010,among 10 batches of 243 H.scabra bloodstocks,5 batches of parent H.scabra succeeded in sperm releasing and spawning(spawning rate: 50%);1 652.72×104 eggs were produced and 1 226.74×104 larvae were hatched out(hatching rate: 74.23%).At water temperature of 27.5~30.0 ℃,it took 32.5 h for the fertilized eggs to finish embryo development.We chose some larvae for 21-day rearing and obtained 19.43×104 early juveniles(size: 0.1 cm) with a survival of 16.7%;after 32-day rearing,2.46×104 late juveniles(size: 0.3~0.5 cm) were obtained with a survival of 2.12%.The study is important for the future natural H.scabra population recovery in Beibu Gulf and its industrialized breeding in South China.

The Effect of Food Quality and Rearing Density on the Growth and Survival of Epibenthic Juveniles of the Sea Cucumber Holothuria scabra

Abstract—Seven combinations of aquatic plant extracts were tested to feed juveniles of H. scabra: Thalassia hemprichii, T. hemprichii with 3 % Spirulina, Sargassum latifolium, S. latifolium with 3 % Spirulina, Thalassodendron ciliatum, Syringodium isoetifolium and organic biofilm. A control test consisted in rearing epibenthic juveniles in tank without any food supply. The results showed that extracts of S. latifolium with or without Spirulina gave the best growth and high survival rates: the mean epibenthic volumes were 112 +/- 55 mm³ and 81 +/- 21 mm3 and the survival rates were 60 and 68 % respectively at the end of the experiment (8 weeks). Rearing densities of 150, 300, 450 and 600 individuals m m-2 were tested. The best survival rates (greater than 60 %) were observed in the batches with an initial density of 450 individuals m m-2 or less. The best growth rate was observed with an initial rearing density of 150 individuals m-². The study of biomass showed that the optimum level for the rearing density is 450 +/- 150 juveniles m m-2 . When the parameters of survival, growth rate and biomass (expressed in volume) are all taken into consideration, the optimum rearing density suggested for epibenthic juveniles of H. scabra is between 300 and 450 individuals m-2 . Keywords: Holothuria scabra, epibenthic juveniles, rearing, survival, growth

Diel burying by the tropical sea cucumber Holothuria scabra: effects of environmental stimuli, handling and ontogeny

Understanding concealment behaviour of marine animals is vital for population surveys and captive-release programmes. The commercially valuable sea cucumber Holothuria scabra Jaeger 1833 (Holothuroidea) can display a diel burying cycle, but is it widely predictable? Circadian burying of captive H. scabra juveniles, and both juveniles and adults in the wild, was examined in New Caledonia. Groups of ten cultured juveniles in mesh chambers in a tank were monitored for 24 h. Small juveniles (1–5 g) displayed an expected diel cycle of epibenthic foraging in the afternoon and night then burial in sediments in the morning. Burial was related significantly to both light and temperature in combination. Similar groups of juveniles were handled once or three times a day for 1 week then frequency of emergence during another week was compared to unhandled controls. Handling stress, whether occasional or frequent, significantly suppressed the frequency of their afternoon emergence from sediments for 4 days. In a coastal seagrass bed, burial and emergence of H. scabra were monitored during days of opposing tidal cycles in three seasons. Adults seldom buried during the day except in the cool season. At that site, most small hatchery-produced H. scabra juveniles were buried during most of the day, while larger juveniles showed little diurnal burying. This study underscores that the circadian behaviours of marine animals can exhibit substantial spatial variation, may be absent at certain sites or seasons, and can be mediated by a complexity of factors that vary over short timescales.

Effective fluorochrome marking of juvenile sea cucumbers for sea ranching and restocking

Dermal spicules (or ‘ossicles’) of cultured sea cucumbers can be fluorescently marked with tetracycline and calcein for sea ranching and restocking but optimal immersion conditions are unknown. Lethal and non-lethal effects, and the efficacy of marking spicules in juvenile sandfish ( Holothuria scabra), were examined under different immersion conditions. Fluorescence brightness and the proportion of marked spicules generally increased with concentration and duration of immersion. Frequency of burial (an indicator of stress) in sandfish increased with both fluorochromes at concentrations above 50 mg L − 1 . Growth in the two weeks post-marking was unaffected at immersion concentrations of 50 and 100 mg L − 1 compared to controls, but appeared inhibited by immersion in solutions of 200 and 400 mg L − 1 of tetracycline or calcein. Sequential marking by tetracycline (yellow) and calcein (green), in either order, showed that calcein was deposited in a higher proportion of spicules. Three other fluorochromes with disparate colors, alizarin complexone, calcein blue and xylenol orange, also marked sandfish spicules and expanded the variety of dichromic combinations. Both tetracycline and calcein fluoresced more brightly when juveniles were marked at 26 or 30 °C than at 21 °C, and this low temperature appears also to reduce the proportion of spicules marked by tetracycline. Our findings show that seawater temperature should be regulated for ex situ immersion marking. The behavioral and biological sensitivities of sandfish demand care in administering the fluorochromes. Fluorochrome immersion at 100 mg L − 1 for 24 h at ≥26 °C provides a practical compromise between minimizing the fitness of released juveniles and ensuring the efficacy of the markers for studies on the growth and survival of sea cucumbers stocked in the wild.

Two New Cytotoxic Triterpene Glycosides from the Sea CucumberHolothuria scabra

Two new triterpene glycosides, scabraside A (1) and B (2), and a structurally known compound (3), were isolated from the sea cucumber Holothuria scabra (Holothuriidae) collected from the South China Sea. Structure of these compounds was elucidated by spectroscopic and chemical methods. The glycosides 1 and 2 exhibit the same common structural features, i. e., the presence of 12- and 17-hydroxy groups in the holostane-type triterpene aglycone with a 9(11)-ene bond, but are different in the side chains of the triterpene aglycone. The glycosides 1 and 2 had significant in vitro cytotoxicity against four human tumor cell lines in comparison to 10-hydroxycamptothecin.

The timing and reproductive output of the commercial sea cucumber Holothuria scabra on the Kenyan coast

The sea cucumber Holothuria scabra is a widely distributed and economically important species that has been harvested in Kenya for decades. No previous studies have been carried out on the reproduction of this species in Kenya. Standard gonad index methods were used to analyze reproductive patterns of individuals collected monthly in 1998–1999, 2000–2001 and 2006–2007. Morphological characteristics, gonad tubule lengths and fecundity were also measured. Mean monthly gonad indices were significantly correlated between males and females indicating synchronous gonad development between the sexes. Gonad indices showed a biannual pattern that was consistent in all three years with a minor spawning event occurring between August and September and a major spawning event between November and December. The pattern of gonad growth showed significant variability between years and between months. Temporal changes in gonad growth correlated significantly with gonad tubule length and absolute fecundity. Monthly gonad indices also correlated significantly with monthly measurements of air temperature and light suggesting a possible role for both factors in timing gametogenesis and spawning. There was a shift in sex ratio from unity in the 1998–1999 and 2000–2001 samples to significantly more males in the 2006–2007 samples, as well as a significant reduction in mean sizes (body wall weight) and reproductive output (gonad index) which suggests that the reproductive success of this species is potentially negatively affected by fishing.

Taxonomy of the heavily exploited Indo-Pacific sandfish complex (Echinodermata: Holothuriidae)

Two commercially valuable holothurians, the sandfish and golden sandfish, vary in colour and have a confused taxonomy, lending uncertainty to species identifications. A recent molecular study showed that the putative variety Holothuria (Metriatyla) scabra var. versicolor Conand, 1986 (‘golden sandfish’) is a distinct species from, but could hybridize with, H. (Metriatyla) scabra Jaeger, 1833 ('sandfish'). Examination of the skeletal elements and external morphology of these species corroborates these findings. The identity of H. (M.) scabra is unambiguously defined through the erection and description of a neotype, and several synonyms have been critically re-examined. The nomenclaturally rejected taxon H. (Metriatyla) timama Lesson, 1830 and H. (M.) scabra var. versicolor (a nomen nudum) are herein recognized as conspecific and are allocated to a new species, Holothuria lessoni sp. nov., for which type specimens are described. The holotype and only known specimen of H. aculeata Semper, 1867, has been found and is redescribed. It is considered to be a valid species. Taxonomic clarification of this heavily exploited species complex should aid its conservation and permit species-specific management of their fisheries. © 2009 The Linnean Society of London, Zoological Journal of the Linnean Society, 2009, 155, 40–59.

A New Triterpene Glycoside from the Sea Cucumber <i>Holothuria Scabra</i> Collected in Vietnam

Bioassay guided fractionation led to the isolation of a new triterpene glycoside, holothurinogenin B (1) along with three known compounds, holothurin B (2), holothurin A (3), and holothurin A2 (4), from the methanol extract of the Vietnamese sea cucumber Holothuria scabra. Their structures were deduced from the spectral analysis (1D-NMR, 2D-NMR, MS) and chemical evidences.

T-antigen binding lectin with antibacterial activity from marine invertebrate, sea cucumber ( Holothuria scabra): Possible involvement in differential recognition of bacteria

In invertebrates, cellular and humoral components are evolved to maintain their body immunity and integrity. Both these factors respond to different antigens such as microorganisms, vertebrate erythrocytes and foreign proteins. In this article, we report a study of a lectin (HSL) involved in immune response in the echinoderm, sea cucumber ( Holothuria scabra). Correlative studies indicate that the expression of this defensive lectin is induced by bacterial challenge, wherein cell wall glycoconjugates of bacteria are involved in lectin induction. HSL showed strong broad spectrum antibacterial activity against both gram-positive and gram-negative bacteria. Under in vitro conditions, purified HSL mediate agglutination of the test bacteria, there by indicating a possible mode of action in physiological situation.

Spatio-Temporal and Size-Dependent Variation in the Success of Releasing Cultured Sea Cucumbers in the Wild

Large-scale releases of cultured “sandfish,” Holothuria scabra, were used to examine size-and density-dependent effects on survival among sites. Juveniles were marked by fluorochromes in 3 size classes and released into open 500-m2 sea pens. A preliminary trial involved the release of 4,000 juveniles at two sites. In a subsequent large-scale experiment, we released 9,000 juveniles at 0.5, 1, or 3 individuals m− 2 at 4 sites. Growth and survival up to 2 years post-release were estimated from successive recapture surveys and marker verification. Most of the surviving animals attained the size at first maturity (180 g) within 12 months in the preliminary trial but grew slower in the second experiment. Growth was density dependent, with carrying capacity at one site of 200–250 g sandfish m−2. Survival varied greatly among sites, explained in part by microhabitat features, but site suitability was ephemeral; previous success at sites did not guarantee success later. Juvenile size at release significantly affected long-term survival, but survival was density-independent within the experimental range. Juveniles should be released at a minimum size of 3 g and at multiple sites and occasions to mitigate spatio-temporal variation in survival. We predict that 7–20% of sandfish released at a size of 3–10 g in optimum habitat could survive to market size, which gives qualified support for restocking. Our results also help to assess the viability of sea ranching, which will depend on sale price, harvest efficiency, and reduced costs of producing juveniles.

Purification and characterization of a T-antigen specific lectin from the coelomic fluid of a marine invertebrate, sea cucumber ( Holothuria scabra)

A novel lectin was purified from the coelomic fluid of the sea cucumber Holothuria scabra (HSL), subjected to bacterial challenge. HSL is a monomeric glycoprotein of molecular mass 182 kDa. The lectin is highly thermostable as it retains full activity for 1 h at 80 °C. Further, the hemagglutination activity of HSL is unaffected by pH in the range 2–11. Unlike other lectins purified from marine invertebrates, the hemagglutination activity of HSL does not require any divalent metal ions. The affinity profile of HSL was studied by a combination of hemagglutination inhibition and fluorescence spectroscopy. HSL binds to desialylated glycoproteins, MeαGal, T-antigen and T (α-ser)-antigen with a distinction between β1–4 and β1–3 linkages. Meα-T-antigen was a potent ligand having highest affinity ( K a 8.32 × 10 7 M −1). Monosaccharide binding is enthalphically driven while disaccharide binding involves both entropic and enthalpic contributions.

Advances in sea cucumber aquaculture and prospects for commercial culture of Holothuria scabra .

Abstract Sea cucumbers have been consumed for centuries in Asia as traditional medicinal and prestige foods, said to aid wound healing, joint pain, intestinal problems and as a general health tonic. Increasing prosperity in China over the past 30 years has fuelled growing demand for high-value seafood products in the region which has placed severe pressure on traditional sea cucumber fisheries. Despite the emergence of new fishery locations and increasing international trade, supply has been failing to meet demand, resulting in an increasing price trend. There is evidence that wild-sea cucumber populations are under severe pressure with concerns that depleted stocks may take decades to recover with no clear indication that fisheries management is improving. Growing interest in stock restoration as a fisheries management tool has led to significant advances in culture techniques for the more valuable species of sea cucumber, and this in turn has raised the possibility of culturing the most promising species commercially. This review provides an overview of sea cucumber ecology and biology, international trade, fisheries management issues and advances in culture techniques, and then focuses on prospects for commercial culture of Holothuria scabra , the most valuable tropical species.

Two New Triterpene Glycosides from the Vietnamese Sea CucumberHolothuria scabra

Two new triterpene glycosides, namely holothurin A3 (1) and A4 (2) were isolated from the methanol extract of the sea cucumber, Holothuria scabra, with their structures elucidated from the spectroscopic evidence (1D NMR, 2D NMR, ESI-MS and HRESI-MS). Compounds 1 and 2 were found to be strongly cytotoxic to both cancer cell lines, KB and Hep-G2, with 50% inhibitory concentrations (IC50) of 0.87 and 0.32 microg/mL (for compound 1) and of 1.12 and 0.57 microg/mL (for compound 2), respectively.

Grow-out of sandfish Holothuria scabra in ponds shows that co-culture with shrimp Litopenaeus stylirostris is not viable

We examined the potential for producing the large numbers of sandfish (Holothuria scabra) needed for restocking programmes by co-culturing juveniles with the shrimp Litopenaeus stylirostris in earthen ponds. Our experiments in hapas within shrimp ponds were designed to detect any deleterious effects of sandfish on shrimp, and vice versa. These experiments showed that a high stocking density of juvenile sandfish had no significant effects on growth and survival of shrimp. However, survival and growth of sandfish reared with shrimp for 3 weeks were significantly lower than for sandfish reared alone. Increased stocking density of shrimp also had a significant negative effect on survival and/or growth of sandfish. A grow-out trial of juvenile sandfish in 0.2-ha earthen ponds stocked with 20 shrimp post-larvae m−2, and densities of sandfish between 0.8 and 1.6 individuals m−2, confirmed that co-culture is not viable. All sandfish reared in co-culture were dead or moribund after a month. However, sandfish stocked alone into 0.2-ha earthen ponds survived well and grew to mean weights of ∼400 g within 12 months without addition of food. The grow-out trial demonstrated that there is potential for profitable pond farming of sandfish in monoculture. Further research is now needed to identify the optimal size of juveniles, stocking densities and pond management regimes.

Density and Size Distribution of the Sea Cucumber, Holothuria scabra (Jaeger, 1935), at Six Exploited Sites in Mahout Bay, Sultanate of Oman

A rapid survey of the density and size distribution of recently exploited populations of Holothuria scabra in Mahout Bay (Ghubbat Hashish Bay) was carried out at six fishing sites. The results showed that population densities varied between 1170 and 4000 individuals ha-1 and biomass ranged between 393 and 2903 kg ha-1. The mean size of sea cucumbers and population densities were much lower in populations closer to human settlements, suggestive of overfishing. The sex ratio was estimated to be 1:1 and the size distributions of males and females did not differ significantly. The length-weight relationship for both sexes was calculated as W (g) = 0.033 Length (mm) 2.178.

Indigenous community-based fisheries in Australia

The commercial sea cucumber species known as Sandfish ( Holothuria scabra) occurs intertidally and subtidally in the Northern Territory of Australia, on or adjacent to Aboriginal land. A 4-yr program of community-based fisheries research with Aboriginal Australians was implemented to assess the viability of indigenous Australians’ involvement in the wild-stock fishery. The research involved extensive and intensive indigenous participation, unusual in Australian biophysical sciences research, during field survey and habitat mapping, complemented by commercial catch data modelling and discussion of its implications. Field surveys produced Sandfish distribution and site-specific density, and revealed some areas that were not commercially fished. Catch data modelling results suggested that no additional effort could be sustained, however commercial fishers increased their effort, expanding their operations into the newly mapped areas. These actions effectively precluded indigenous peoples’ aspirations of entry into the commercial fishery. The efficacy and outcomes of participatory program design with indigenous Australians need critique in the absence of the political will and statutory backing to provide equitable access to resources.