Many plants and animals store toxic or unpalatable compounds in tissues that are easily encountered by predators during attack. Defensive compounds can be produced de novo, or obtained from dietary sources and stored directly without selection or modification, or can be selectively sequestered or biotransformed. Storage strategies should be optimized to produce effective defence mechanisms but also prevent autotoxicity of the host. Nudibranch molluscs utilize a diverse range of chemical defences, and we investigated the accumulation and distribution of defensive secondary metabolites in body tissues of 19 species of Chromodorididae nudibranchs. We report different patterns of distribution across tissues, where: 1) the mantle had more or different (but structurally related) compounds than the viscera; 2) all compounds in the mantle were also in the viscera; and 3) the mantle had fewer compounds than the viscera. We found no further examples of species that selectively store a single compound, previously reported in Chromodoris species. Consistent with other studies, we found high concentrations of metabolites in mantle rim tissues compared to the viscera. Using bioassays, compounds in the mantle were more toxic than compounds found in the viscera for Glossodoris vespa Rudman, 1990 and Ceratosoma brevicaudatum Abraham, 1876. In G. vespa, compounds in the mantle were also more unpalatable to palaemonid shrimp than compounds found in the viscera. This indicates that these species may modify compounds to increase bioactivity for defensive purposes and/or selectively store more toxic compounds. We highlight clear differences in the storage of sequestered chemical defences, which may have important implications for species to employ effective defences against a range of predators.

Four new diterpenoids, australins E–H (1–4), have been isolated from the marine soft coral Cladiella sp. collected in Pohnpei. The structures of 1–4 were elucidated by analysis of their NMR and mass spectrometry data combined with an X-ray diffraction analysis of australin E (1). Australin E (1) activates the inositol 5-phosphatase SHIP1 in vitro.

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Abstract. Patantis G, Dewi AS, Fawzya YN, Nursid M. 2019. Identification of Beche-de-mers from Indonesia by molecular approach. Biodiversitas 20: 537-543. Sea cucumbers have been commercially traded around the world due to their nutritional values and health benefits. Sea cucumbers are marketed as processed sea cucumber, also known as beche de mer, teripang, haisen or gamat. Due to the high global demand of beche-de-mers, there have been several cases of fraud due to the visual shape and color similarities of processed sea cucumbers. Additionally, the local name diversity of Indonesian sea cucumbers making the identification of beche-de-mers difficult. Therefore, this study aimed to identify commercial sea cucumbers from selected locations in Indonesia by molecular approach. The targeted Cytochrome c oxidase subunit I (COI) was used in this research. A total of 25 beche-de-mers was purchased from local markets in Indonesia, i.e. Boalemo (17 local names), Pesawaran (5), Surabaya (2) and West Lombok (1). Results showed that 22 species of beche-de-mer were successfully identified, ie. Acaudina sp., Actinopyga echinites, A. lecanora, A. miliaris, Bohadschia argus, B. marmorata, B. ocellata, B. vitiensis, Holothuria sp. H. atra, H. coluber, H. edulis, H. excellens, H. fuscocinerea, H. fuscogilva, H. fuscopunctata, H. scabra, Pearsonothuria graeffei, Phyrella sp., Stichopus herrmanni, S. horrens and S. monotuberculatus. The identification of Indonesian beche-de-mers using molecular method could support the identification of the local sea cucumbers to overcome mislabeled and fraud. Correct identification is important for the record of beche-de-mer trade in Indonesia and further conservation management.