Crinoid diversity and their symbiotic communities at Bangka Island (North Sulawesi, Indonesia)

Members of the order Comatulida (Echinodermata: Crinoidea) are widely distributed on Indo-Pacific reefs, where they host a highly diverse and understudied cryptofauna, which makes them a potential source of hidden biodiversity. In this study, shallow-water crinoid populations and their symbiotic communities from the Bangka Archipelago (North Sulawesi, Indonesia) were investigated. Presence and diversity of the symbionts, focusing on their host selectivity patterns, were assessed. A total of 39 comatulid species belonging to six families were found. Overall, symbiont fauna included 70 species belonging to 11 families within eight orders. The results showed variable host specificity among symbionts’ families, and patterns correlated with host size for some symbiont taxa. This study provides the first baseline dataset of crinoid assemblages and their symbiont diversity in the understudied region of North Sulawesi, within the Coral Triangle