Uncovering the Brittle Star’s Genetic Diversity from Kalimantan and Bali

Abstract Brittle star is a benthic organism that belongs to Echinodermata and plays an important role as a detritivore that balances the food chain in coral reef ecosystems. Several factors, including anthropogenic pressures, climate change, over-exploitation, and pollution, are known to threaten the brittle star’s biodiversity. Therefore, species identification research using molecular methods is essential. Molecular analysis can be conducted using the Cytochrome Oxidase I marker of mitochondrial genome DNA (mtDNA). The sequencing results will be compared with NCBI data to find the closest species. 5 of the total 8 samples were successfully sequenced, identifying three species: Ophiocoma schoenleinii, Breviturma pusilla, Ophiactis savignyi, and Ophiuroidea sp. The comparison of sequencing results with existing NCBI data yielded genetic distances ranging from 0.000 to 0.129. The genetic distance among clades ranged from 0.010 to 0.355. A phylogenetic tree was constructed to examine the relationships between our findings and brittle star data from various countries. We included data from 11 countries: Papua New Guinea, Australia, the United States, New Zealand, Canada, the West Indies, South Africa, South Korea, Brazil, Belgium, and France. Based on the distribution map, the research results are most closely related to data from Papua New Guinea.