Colobocentrotus Atratus Research Articles

STUDY OF NUTRITIONAL CONTENTS OF SEA URCHIN GONAD FROM DRINI BEACH, GUNUNG KIDUL, YOGYAKARTA

ABSTRACTThis paper aims to determine the types and contents of protein, fatty acids, amino acids and protein in the gonads of Arbacia lixula, Colobocentrotus atratus, Heterocentrotus trigonarius and Echinotrix diadema from the waters of Drini, Gunung Kidul, Yogyakarta. Kjedal method was used to analyze the protein content, while GC and HPLC methods were employed to analyze amino acids in this study. The results showed that the protein contents of each sample, consequently from highest to lowest, were Heterocentrotus trigonarius (13.3 %), Echinotrix diadema (10.86), Colobocentrotus atratus (10.41) and Arbacia lixula (9.90%). Amino acids analysis from all identified both saturated fatty acids, consisting of lauric acid, myristic acid, palmitic acid, stearic acid, arachidonic acid, lignoceric acid, as well as non-saturated fatty acids, consisting of palmitoleic acid, oleic acid, linoleic acid, erucic acid, EPA, and DHA. The highest contents of non-saturated fatty acids were identified in Colobocentrotus atratus (434.14 mg/100g) and the lowest content in Arbacia lixula (197.71 mg/100g). The highest percentage of essential fatty acids was found in Heterocentrotus trigonarius (0.29%), whereas the lowest was found in Echinotrix diadema (0.19 %). It is concluded that the gonad of Heterocentrotus trigonarius showed the highest protein and essential fatty acids contents. This study also found that Colobocentrotus atratus sea urchin gonads possess the highest content of non-saturated fatty acids (434.14 mg/100g). Keywords: amino acid, fatty acid, protein, sea urchin gonad.

The diversity of Echinoderm in Sarangan beach, Gunung Kidul, Yogyakarta

Sarangan beach at the coast of Gunung Kidul is dominated by substrates of sand, coral, and macroalgae where Echinodermata was found. This research was conducted to determine the diversity of echinoderms on that beach. Field observation was carried put during maximum low tide. Sampling was carried out by applying random sampling method. Specimens were preserved and identified. The sampled specimens consisted of a member of class Asteroidea (Anthenea sp), members of Ophiuroidea (Ophiocoma scolopendrina, Ophiomastix annulosa, and Ophiocoma erinaceus), members of Echinoidea (Colobocentrotus atratus, Heterocentrotus trigonarius, Stomopneustes variolaris, and Echinometra sp.).

Sea urchins: Improving understanding of prehistoric subsistence, diet, foraging behavior, tool use, and ritual practices in Polynesia

Sea urchins (echinoids) were integrated into many aspects of prehistoric Oceanic society as they provided food, raw material for abrading tools and rare ornaments, and were used as offerings on shrines (ko‘a) in the Hawaiian Islands. We privilege seven habitation and shrine assemblages (mostly dating to late prehistory; i.e., post AD 1500s) situated along a ∼12-km length of the rocky windward coast of Moloka‘i, Hawaiian Islands, where some of the densest concentrations of urchins have been recorded from Oceania. We examined >185,000 urchin fragments weighing nearly 11.7 kg which, we believe, is the largest analyzed sample to date. Focusing primarily on the helmet urchin (Colobocentrotus atratus), found throughout the Indo-Pacific, we used a protocol for accurately calculating the minimum numbers of individuals using unique test (endoskeleton) plates and internal mouthparts, demonstrated the dietary importance of urchins for marine subsistence, constructed an allometric formula for calculating individual urchin size, and discussed the relevance of urchins for monitoring long-term human impacts to this important coastal resource. While the study sites contained overwhelmingly limpets (Cellana spp.), urchins supplied >80% fat and nearly 40% protein of some of the invertebrate assemblages. It was documented that slightly larger urchins were placed as offerings on a shrine in contrast to smaller individuals associated with habitation structures.

Kekayaan Jenis Bulu Babi (Sea Urchin) di Kawasan Perairan Pantai Gunung Kidul, Yogyakarta

Pantai Gunung Kidul memiliki beberapa biota laut salah satunya bulu babi (Echinodermata). Penelitian ini bertujuan mengidentifikasi jenis bulu babi di kawasan perairan pantai Gunung Kidul, Yogyakarta. Penelitian bulu babi di kawasan perairan pantai Gunung Kidul dilakukan pada bulan April sampai dengan Mei 2018 di 3 (tiga) lokasi yaitu Pantai Drini, Pantai Ngrenehan, dan Pantai Widodaren. Pengambilan data dilakukan dengan menggunakan metode transek kuadrat ukuran 1m x 1m. Dari hasil penelitian diperoleh 7 (tujuh) jenis bulu babi yang tergolong dalam 4 (empat) famili dan 3 (tiga) ordo. Jumlah jenis bulu babi yang paling banyak ditemukan di Pantai Widodaren, dengan total 6 (enam) jenis, yaitu Echinometra sp., Echinometra mathaei, Heterocentrotus sp., Tripneustes ventricosus, Colobocentrotus atratus dan Arbacia lixula. Sedangkan di Pantai Drini dan Ngrenehan ditemukan masing-masing 4 (empat) jenis yaitu Echinometra sp. Echinometra mathaei, Heterocentrotus sp.,dan Stomopneustes variolaris.

Oxygen-limited performance of the intertidal sea urchin Colobocentrotus atratus when submerged

Thermal limits of marine ectotherms are influenced by the dynamics of oxygen supply and demand; all else being equal, as temperature increases, metabolic demand eventually outpaces an organism's capacity for oxygen uptake and delivery. We tested the combined effects of oxygen and temperature on an intertidal wave-zone obligate sea urchin, Colobocentrotus atratus, to examine whether oxygen limitation during submersion may limit the lower vertical distribution of this species. We measured survival and attachment strength under both ambient (21%) and enriched (35%) O2 conditions and at a range of temperatures between 25 and 37 °C. Oxygen enrichment increased survival at warmer temperatures, demonstrating oxygen limitation during submergence at high temperatures. Attachment strength declined with increasing temperature, but, unlike survivorship, was not affected by O2 enrichment. Our data suggest that the lower limit on vertical distributions of C. atratus are set in part by abiotic stresses experienced under immersion, and that hypoxic stress will increase with warming sea temperatures. Thus, warmer oceans may reduce the amount of viable habitat for C. atratus, and other intertidal marine taxa that are specialized for aerial gas exchange, due to increasing abiotic stress at the bottom of their vertical distribution.

Reappearance of the rare Shingle Urchin Colobocentrotus (Podophora) atratus (Camarodonta: Echinometridae) after eight decades from the rocky shore of Kodiyaghat (Port Blair), South Andaman Islands, India

The present work is aimed at facilitating conservation efforts of a rare species of sea urchin (Colobocentrotus atratus) reported nearly eight decades after its initial description by Bell (1887) and later by Clarke (1925) from the coastal waters of south Andaman Islands. Recently, during a three years study (2011-14) on the macrobenthic epifauna along the south Andaman coast, five live specimens of C. atratus were recorded from Kodiyaghat (11031'532''N; 092043'457'' E), south Andaman Islands. Available information shows that this species has reappeared in the south Andaman Islands seventy nine years after the citation by Sastry (1994) collected in the year 1935. The disappearance of this species from the literature in the intermittent years and a sparse population in coastal reaches of south Andaman Islands at present suggest that this species makes a candidate taxa for inclusion in the list of ‘endangered’ or ‘vulnerable’ Indian marine species following IUCN Red List criteria to Wild species.

Discovery of urchin-associated densoviruses (family Parvoviridae) in coastal waters of the Big Island, Hawaii

Echinoderms are important constituents of marine ecosystems, where they may influence the recruitment success of benthic flora and fauna, and are important consumers of detritus and plant materials. There are currently no described viruses of echinoderms. We used a viral metagenomic approach to examine viral consortia within three urchins - Colobocentrotus atratus, Tripneustes gratilla and Echinometra mathaei - which are common constituents of reef communities in the Hawaiian archipelago. Metagenomic libraries revealed the presence of bacteriophages and densoviruses (family Parvoviridae) in tissues of all three urchins. Densoviruses are known typically to infect terrestrial and aquatic arthropods. Urchin-associated densoviruses were detected by quantitative PCR in all tissues tested, and were also detected in filtered suspended matter (>0.2 µm) from plankton and in sediments at several locations near to where the urchins were collected for metagenomic analysis. To the best of our knowledge, this is the first report of echinoderm-associated viruses, which extends the known host range of parvoviruses.

Isolation and characterization of twenty-six, polymorphic microsatellite loci for the tropical sea urchin, Colobocentrotus atratus

Twenty-six, polymorphic microsatellite loci were developed for the tropical sea urchin Colobocentrotus atratus. Microsatellite enriched genomic libraries were constructed and subsequently sequenced using Roche 454 technology. The 26 loci were characterized in 21 individuals from Pulau Asu, Nias, Indonesia. Observed levels of heterozygosity ranged from 0.52 to 1.00 with a mean of 11.9 alleles per locus. No pairs of loci showed evidence of significant linkage disequilibrium and 3 loci significantly deviated from Hardy–Weinberg expectations.

Sniffing Out New Data and Hypotheses on the Form, Function, and Evolution of the Echinopluteus Post-Oral Vibratile Lobe

The performance requirements of ciliary band feeding explain the convoluted forms of many marine invertebrate larvae. Convolutions increase surface area and therefore feeding rates per unit body volume. We review recent advances in morphology, neural development, and behavior at settlement of the echinoid Lytechinus pictus and provide new ultrastructural and expression data on larvae of its congener, L. variegatus. Larvae of the echinometrid Colobocentrotus atratus contain neurons identified by their expression of nitric oxide synthase (NOS), indicating that this character is not unique to Lytechinus. We hypothesize that in some echinoids the convoluted shape of the post-oral vibratile lobe (POVL) covaries with the distribution of identified sensory neurons to enable olfaction during settlement. An analysis of variation in structural elaboration of the post-oral transverse ciliary band (PTB) within Echinoida and in feeding larvae of other echinoderm classes indicates that only echinoids, but not all echinoids, possess this novel character; larvae that do are distributed heterogeneously within the class. In recognition of this specialized function for the POVL and surrounding ectoderm, and because it is lobate and grows toward the mouth, we propose naming this structure the adoral lobe.

Estimation of the attachment strength of the shingle sea urchin, Colobocentrotus atratus, and comparison with three sympatric echinoids

The peculiar limpet-like morphology of the genus Colobocentrotus is unique among the regular echinoids. This shape has been interpreted as an adaptation to life in areas of extreme wave exposure. In this study the attachment strength of C. atratus is compared with that of three sympatric species, Echinometra mathaei, Heterocentrotus trigonarius and Stomopneustes variolaris, which have more typical echinoid morphology and live in different microhabitats. For each species, the adhesion of individual sea urchins was measured as well as the tenacity of single tube foot and the mechanical properties of the tube foot stems. Colobocentrotus always presented the highest measured values, although not always significantly different from those of the other species. Of the mechanical properties of the stem measured, the stem extensibility was the only property that was significantly different among species. In general the stems of all the species studied became more extensible and more difficult to break with increasing strain rate, providing an adaptative advantage to the sea urchin when subjected to rapid loads such as waves. In terms of single tube foot tenacity, C. atratus tube feet attached with a tenacity (0.54 MPa) two times higher than the one of E. mathaei, H. trigonarius and S. variolaris (0.21–0.25 MPa). Individual sea urchins of the four species, however, attached with a similar strength (0.2–0.26 MPa). The calculation of safety factors showed that it is the very high number of adoral tube feet of C. atratus and not the overall shape of the animal that allows this species to withstand very high water velocities. However, C. atratus streamlined morphology may be a functional adaptation to reduce the impact of other hydrodynamic forces (such as wave impingement forces) or to cope with other selective environmental stresses (such as dessication), and thus to inhabit extremely exposed areas of the intertidal.

Why the urchin lost its spines: hydrodynamic forces and survivorship in three echinoids

Two species of sea urchins (Colobocentrotus atratus and Echinometra mathaei) commonly co-occur on wave-swept intertidal shores in the Indo West Pacific. E. mathaei is a typical spiny urchin and is confined to cavities in the rock. In contrast, C. atratus has an unusual morphology, in which the spines are much reduced, and is found on substrata fully exposed to wave-induced velocities and accelerations. Previous researchers have suggested that spine reduction may therefore be a morphological adaptation to hydrodynamic forces. However, measurement of the drag, lift and accelerational forces on sea urchins show that the adaptive significance of spine reduction is less straightforward than it initially appears. The reduction in drag in C. atratus as compared with that in E. mathaei is to a large extent offset by an increase in lift. Instead, the 'streamlined' morphology of C. atratus seems best adapted to provide a reduction in the force imposed by water acceleration, thereby making it feasible for C. atratus to venture safely into the tumultuous flows of the surf zone.

PHYSICAL PROPERTIES OF GAMETES IN THREE SEA URCHIN SPECIES

Physical properties (density in kg m-3, viscosity, sinking rates and dispersion rate) of the gametes and associated spawned materials were measured for three species of sea urchin, Tripneustes gratilla, Echinometra mathaei and Colobocentrotus atratus, from habitats that differ in wave exposure. The gametes of all three species are negatively buoyant, highly viscous and exhibit shear-thinning (a decrease in viscosity with increasing shear rate). Female gametes are more viscous than male gametes, and the viscosity of female gametes differs among the three species. The viscosity of female gametes is highest for C. atratus, the species from habitats most exposed to wave action. Within the species T. gratilla, viscosity of female gametes is higher in habitats exposed to wave action than in more protected habitats. Evidence reported in this paper suggests that the shear-thinning of gametes may provide a performance advantage for these sea urchins. High viscosity of gametes at low shear rates may decrease gamete dispersal upon release and, under certain flow conditions, allow gametes to form strings and clumps on the surface of the urchin. Depending upon the morphology of the surface, these clumps or strings may be retained and fertilization may occur within these clumps or strings. Conversely, low viscosity of gametes at high shear rates decreases the power required to extrude gametes through the gonoduct during spawning.

Sea urchin morphogenesis and cell–hyalin adhesion are perturbed by a monoclonal antibody specific for hyalin

We have generated and characterized a monoclonal antibody (McA Tg-HYL) that recognizes sea urchin hyalin as evidenced by immunofluorescence staining of the hyaline layer (HL) and immunoblot staining of the hyalin protein band. On immunoblots of HL extracts only the hyalin protein reacted with McA Tg-HYL. Immunoprecipitates of radioactive proteins from embryos incubated with [35S]methionine yielded radioactive hyalin and 190, 140 and 105 x 10(3) Mr proteins associated with hyalin. McA Tg-HYL was generated against Tripneustes gratilla embryos but reacts with hyalin from the distantly related sea urchin species, Colobocentrotus atratus, Strongylocentrotus purpuratus, Arbacia punctulata, Lytechinus variegatus and Lytechinus pictus. Developing embryos of the above-mentioned six species were treated with McA Tg-HYL and did not gastrulate or form arms. Observations of treated embryos revealed areas of separation of the hyaline layer from the underlying embryonic cells, suggesting that McA Tg-HYL was interfering with binding of the cells to the HL. Using the centrifugation-based adhesion assay of McClay et al. (Proc. natn. Acad. Sci. U.S.A. 78, 4975-4979, 1981), Fab' fragments of McA Tg-HYL were found to inhibit cell-hyalin binding. McA Tg-HYL did not inhibit hyalin gelation in vitro or the reaggregation of dissociated blastula cells. We postulate that McA Tg-HYL recognizes an evolutionarily conserved hyalin domain involved in cell-hyalin binding and required for normal epithelial folding.

Comparative morphometrics of echinoderm larvae. I. Some relationships between egg size and initial larval form in echinoids

Egg protein content, and presumably total organic content (parental investment), was linearly related to egg volume among seven species of echinoids with planktotrophic larval development: Strongylocentrotus droebachiensis (O.F. Müller), S.purpuratus (Stimpson), S.franciscanus (A. Agassiz), Dendraster excentricus (Eschscholtz), Heterocentrotus mammillatus (Klein), Colobocentrotus atratus (Linnaeus), and Tripneustes gratilla (Linnaeus). Initial larval size and feeding capability, at the 2-armed and 4-armed pluteus stages, were positively correlated with egg size. The complexity of larval shape, as ciliated band length or total arm length relative to body length, was independent of egg size. Initial feeding efficiency, defined as the ratio of feeding capability to larval respiratory electron transport system (ETS) activity, was inversely related to egg size. This was the result of a strong dependence of metabolism on body size. Important differences in the egg size and larval form relationships were observed among the different echinoid families and between geographic regions. It is predicted that species with larger eggs and larger initial larvae will either remain larger at each stage of development or develop to a given stage faster than species with small eggs. These relationships between egg size and larval form may constrain selection for certain reproductive or larval traits such as egg size, fecundity, larval form, development rate, total development period, and size at metamorphosis, thereby limiting the evolutionary flexibility of reproductive pattern.

Longevity, Life History, and Relative Body Wall Size in Sea Urchins

Annual survival rates in 38 populations of 17 sea urchins species in the Indo—West Pacific were related to relative size of the body wall and exposure to the surf. The urchin species are: Heterocentrotus trigonarius, H. mammillatus, Colobocentrotus atratus, Echinometra mathaei, E. oblonga, and Heliocidaris erythrogramma in the family Echinometridae; Prionocidaris baculosa in the Cidaridae; Stomopneustes variolaris in the Stomopneustidae; Echinothrix calamaris, E. diadema, Centrostephanus rodgersi, Diadema paucispinum, and D. setosum in the Diadematidae; Tripneustes gratilla, another Tripneustes sp. (possibly the same as T. gratilla), and Toxopneustes pileolus in the Toxopneustidae; and Salmacis belli in the Temnopleuridae. Populations were studied at Hawaii, Enewetak Atoll, Queensland, New South Wales and Western Australia, Sri Lanka, Seychelles, Kenya, Zanzibar, and Israel (Eilat). Live animals were dissected to determine the size of body components. The relative size (mass) of the body wall for a species is expressed by the constant α in the equation B = αTb, where B is wet mass of the body wall and T is total wet mass. A common β value of 0.976 ± 0.004 (SE) was used for all species, so α values can be used to compare relative body wall sizes among species. Values of α ranged from 0.966 for Heterocentrotus trigonarius (Enewetak Atoll) to 0.360 for Salmacis belli (Moreton Bay, Queensland, Australia). Parameters of the Richards growth function were determined from animals tagged with tetracy—cline. Tagged animals were collected after they had been in the field for 1 yr. Growth parameters were used with parameters from size—frequency distributions to estimate Z, the mortality coefficient. Annual survival probability p is e—z. Stepwise multiple regression was used to examine the relationship between annual survival probability (p) and two independent variables, α and E, where E is a subjective measure of exposure to surf (1 = most exposed). The function is p = 1.20α + 0.061E — 0.350. Survivorship increases with increased relative size of the body wall and with increased protection from the surf. The positive relationship between survival probability and relative body wall size supports the hypothesis that survival is related to allocation of resources to maintenance. The significance of longevity in urchins probably is that it is related to the predictability of survival of prereproductive individuals. The greater the unpredictability, the longer life must be. Long life requires a greater investment in maintenance mechanisms and hence, among other adaptations, a more massive body wall.

Localized activation of bending in proximal, medial and distal regions of sea-urchin sperm flagella.

ABSTRACT Spermatozoa from the sea urchin, Colobocentrotus atratus, were partially demembranated by extraction with solutions containing Triton X-100 at a concentration which was insufficient to solubilize the membranes completely. The resulting suspension was a mixture containing some spermatozoa in which a proximal, medial, or distal portion of the flagellum was membrane covered, while the remaining portion was naked axoneme. In reactivating solutions containing 12 μ M ATP, only the naked portions of the flagellum became motile. In reactivating solutions containing 0·8 mM ADP, the membrane-covered regions became motile and beat at 6–10 beats/s, while the naked regions remained immobile, or beat very slowly at about 0·3 beat/s. Activation of membrane-covered regions in ADP solutions probably results from the membrane restricting the diffusion of ATP which is formed from ADP by the axonemal adenylate kinase. The results indicate that any region of the flagellum has the capacity for autonomous beating, and that special properties of the basal end of the flagellum are not required for bend initiation. How ever, the beating of different regions of the flagellum is not completely independent, for in a fair number of spermatozoa the beating of the distal, membrane-covered region in 0·8 mM ADP was intermittent, and was turned on and off in phase with the much slower bending cycle in the proximal region of naked axoneme.

Direct isolation of the hyaline layer protein released from the cortical granules of the sea urchin egg at fertilization.

Treatment of the eggs of the sea urchin with a 1 M solution of glycerol at fertilization allows the recovery from this solution of the protein released from the cortical granules, including that which would normally give rise to the hyaline layer. The calcium-gelable protein previously extracted from whole eggs and from isolated cortical material was found to be present in the glycerol solution, confirming its localization in the cortical granules and its role in the hyaline layer. Quantitative measurements on the eggs of two Hawaiian species, Colobocentrotus atratus and Pseudoboletia indiana, which have the widest variation in the gel protein content, demonstrated that a proportionate amount of this material was released at fertilization in these species, which correlates with the thickness of the hyaline layer in the two cases. In addition, the calcium-insoluble fraction of Sakai can be extracted from these eggs after removal of the hyaline protein by glycerol, showing that this is a different material. A simple method for the separation of the hyaline protein from the calcium-insoluble fraction in solution is provided.