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National Committee on Marine Sciences (NCMS)

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Has files: NoScientific name: search.filters.scientificname.Stichopus horrens

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    Associated effects of shading on the behavior, growth, and survival of Stichopus cf. horrens juveniles
    Rioja, Rose Angeli; Palomar-Abesamis, Nadia; Juinio–Meñez, Marie Antonette (Springer Science and Business Media LLC, 2021-07-07)
    Stichopus cf. horrens is an emergent culture species. It is known to be nocturnal and negatively phototactic; hence, determining its behavioral and growth responses to different light regimes is essential in optimizing culture protocols. This study examined the interactive effects of shading and relative food availability on the feeding pattern, absolute growth rates, and survival of juvenile S. cf. horrens. Six-month-old juveniles (4.27 to 19.41 g) were reared in replicate aquaria with three different shading treatments (covered, exposed, and half-covered aquaria) under ambient light conditions for 30 days. Juveniles in the exposed treatment with high microalgal biomass (13.44 ± 4.57 mg/g) had the highest growth rates (0.10 ± 0.05 g/day) but also the highest mortality (50%). In contrast, juveniles in the covered treatment had the lowest growth (−0.07 ± 0.03 g/day) but the highest survival (100%). Growth rates in the half-covered treatment were comparable with the exposed, and survival was higher than in the covered treatment. These indicate a trade-off between growth associated with more food and mortality risks due to light-induced stress. Juveniles in the half-covered treatment showed a significant preference to stay in the shaded portion whenever they were inactive during the day, suggesting avoidance to high light intensities (4726.51 ± 1582.43 Lux). Results of this study suggest that careful calibration of light intensities in nursery systems may help enhance juvenile growth. For indoor systems that may have limited space or surfaces for microalgal growth, cultured benthic diatom can be added to the partially covered tanks to increase the food available for the juveniles.
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    BFAR Administrative Circular No. 248: Series of 2013. Size regulation for sea cucumber collection and trade.
    (Bureau of Fisheries and Aquatic Resources, 2013-11-25)
    This Circular, consisting of 7 sections and two Annexes, establishes Size Regulation for Sea Cucumber Collection and Trade. Pursuant to Section 11 of Republic Act No. 8550 and Sections 22 and 25 of Fisheries Administrative Order (FAO) No. 233 implementing R.A. No. 9147, the following rules and regulations for the conservation of sea cucumber species belonging to the orders: Aspidochirotida and Dendrochirotida in Philippine waters are hereby promulgated. It shall be unlawful for any person, association or corporation to gather, collect, catch, take, cause to be taken or caught sea cucumber species for commercial trade without an AWCP or to transport without LTP. It shall also be unlawful for any person, association or corporation to possess, transport, sell, trade or export sea cucumber species in any state or form except in dried form with minimum size of 2 inches or 5 centimeters in length. Annexes specify the following information: Annex A lists the Common Commercial Sea Cucumber Species in the Philippines; and Annex B lists the Common Commercial Sea Cucumber Species in the Philippines in Fresh and Dried Forms.
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    Pseudocryptic diversity and species boundaries in the sea cucumber Stichopus cf. horrens (Echinodermata: Stichopodidae) revealed by mitochondrial and microsatellite markers
    Lizano, Apollo Marco D.; Kim, Kenneth M.; Juinio-Meñez, Marie Antonette; Ravago-Gotanco, Rachel (Nature Research, 2024)
    Morphologically cryptic and pseudo-cryptic species pose a challenge to taxonomic identification and assessments of species diversity and distributions. Such is the case for the sea cucumber Stichopus horrens, commonly confused with Stichopus monotuberculatus. Here, we used mitochondrial cytochrome oxidase subunit I (COI) and microsatellite markers to examine genetic diversity in Stichopus cf. horrens throughout the Philippine archipelago, to aid species identification and clarify species boundaries. Phylogenetic analysis reveals two recently diverged COI lineages (Clade A and Clade B; c. 1.35–2.54 Mya) corresponding to sequence records for specimens identified as S. monotuberculatus and S. horrens, respectively. Microsatellite markers reveal two significantly differentiated genotype clusters broadly concordant with COI lineages (Cluster 1, Cluster 2). A small proportion of individuals were identified as later-generation hybrids indicating limited contemporary gene flow between genotype clusters, thus confirming species boundaries. Morphological differences in papillae distribution and form are observed for the two species, however tack-like spicules from the dorsal papillae are not a reliable diagnostic character. An additional putative cryptic species was detected within Clade B-Cluster 2 specimens warranting further examination. We propose that these lineages revealed by COI and genotype data be referred to as Stichopus cf. horrens species complex. © The Author(s) 2024.