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AGROVOC Keyword: search.filters.agrovoc.sea cucumbersSDG: search.filters.sdg.SDG 12 - Responsible consumption and production

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    Physicochemical and biochemical characterization of collagen from Stichopus cf. horrens tissues for use as stimuli-responsive thin films
    Sisican, Kim Marie D.; Torreno, Vicenzo Paolo M.; Yu, Eizadora T.; Conato, Marlon T. (American Chemical Society, 2023-09-20)
    The mutable collagenous tissue (MCT) of sea cucumber, with its ability to rapidly change its stiffness and extensibility in response to different environmental stress conditions, serves as inspiration for the design of new smart functional biomaterials. Collagen, extracted from the body wall of Stichopus cf. horrens, a species commonly found in the Philippines, was characterized for its suitability as stimuli-responsive films. Protein BLAST search showed the presence of sequences commonly found in type VII and IX collagen, suggesting that Stichopus horrens collagen is heterotypic. The maximum transition temperature recorded was 56.0 ± 2 °C, which is higher than those of other known sources of marine collagen. This suggests that S. horrens collagen has better thermal stability and durability. Collagen-based thin films were then prepared, and atomic force microscopy (AFM) imaging showed the visible collagen network comprising the films. The thin films were subjected to thermomechanical analysis with degradation starting at >175 °C. At 100–150 °C, the collagen-based films apparently lose their translucency due to the removal of moisture. Upon exposure to ambient temperature, instead of degrading, the films were able to revert to the original state due to the readsorption of moisture. This study is a demonstration of a smart biomaterial developed from S. cf. horrens collagen with potential applications in food, pharmaceutical, biomedical, and other collagen-based research.
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    Transcriptome-derived SNP markers for population assignment of sandfish, Holothuria (Metriatyla) scabra
    Ordoñez, June F.; Ravago-Gotanco, Rachel (Elsevier, 2024-01-30)
    The sandfish, Holothuria scabra is a commercially important fishery and aquaculture species contributing to the high-value sea cucumber industry. Overexploited across many areas throughout its distributional range, natural populations are considered in decline. Accurate genetic assignment to population of origin is becoming increasingly important for genetics-based marine fisheries management and monitoring, especially for species experiencing depletion of natural stocks and decline in fisheries productivity due to overfishing and illegal, unreported, and unregulated (IUU) fishing. Initiatives for genetics-based applications on economically important seafood such as H. scabra have been limited by the lack of comprehensive genome or transcriptome resources. The present study developed and evaluated the use of gene-associated single nucleotide polymorphism (SNP) markers to assign sandfish to three locations in the Philippines, in the proximity of existing and emerging hatchery production centers. In silico SNP discovery pipeline using pooled RNA-Seq libraries and medium-throughput genotyping approach generated a dataset comprising 115 individuals genotyped at 88 SNPs. Population assignment using machine-learning analysis and Bayesian approach revealed that the 88 transcriptome-derived SNPs allowed the assignment of sandfish individuals to population of origin, with an overall assignment accuracy of >80%. The novel SNPs developed could find their utility in facilitating the development of geographic traceability tools applicable in the context of sandfish aquaculture, fisheries management and conservation.
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    Metamorphic success and production cost of Holothuria scabra reared on microalgae concentrates compared with live microalgae
    Garpa, Tomilyn Jan; Caasi, Olivier Josh C.; Juinio–Meñez, Marie Antonette (Bureau of Fisheries and Aquatic Resources, 2024-03-07)
    The production of live microalgae poses challenges for the expansion of sandfish hatcheries, hindered by high costs and limited technical resources. In relation to this, the use of three imported commercial concentrates (Instant Algae®) - TW1200 (Thalassiosira weisflogii), TISO1800 (Isochrysis sp.), and Shellfish1800 (mixed diatom) - were compared with live Chaetoceros calcitrans (CC). The diet efficacy was evaluated based on larval development, growth, and survival to late auricularia (LA) with hyaline spheres (HS), and the number of post-settled juveniles. Larvae reared with TW did not progress beyond LA, while those fed CC exhibited earlier LA development, larger sizes (1028.43 ± 19.38 µm), and significantly more post–settled juveniles (9,268 ± 2,183.79) compared to SHELL and TISO. Although TISO larvae reached a larger size during LA (855.7 ± 62.67 µm), SHELL resulted in a higher number of post-settled juveniles. The better performance of CC and SHELL may be attributed to their higher carbohydrate content. Despite SHELL and TISO having lower juvenile yields and longer feeding durations, the estimated cost per juvenile using SHELL, TISO, and CC were PHP 2.00, PHP 11.77, and PHP 0.52, respectively. Results showed that microalgae concentrates are not a cost-effective option under the studied conditions. The potential use of microalgae concentrates as supplemental feeds and further research to develop the use of local microalgae concentrates to sandfish larval culture are discussed.