First Report on the Species Composition of the Nike Fish (Gobiidae) in the Coastal Waters of Bolaang Mongondow Raya, North Sulawesi, Indonesia

The Nike fish (family Gobiidae) are ecologically and economically significant components of the coastal ecosystems in Bolaang Mongondow Raya, North Sulawesi Province. However, morphological identification of Nike fish species presents challenges due to high similarities in physical characteristics among species. This study aimed to accurately identify Nike fish species and evaluate their genetic diversity using a molecular approach, thereby providing insights into species composition and potential cryptic diversity in the region. The study was carried out between February and March 2025 at the Laboratory of Fisheries and Marine Science, UNSRAT Manado, and the Indonesian Biodiversity Laboratory (BIONESIA), Bali. A molecular identification technique was employed using DNA barcoding targeting the cytochrome oxidase subunit I (COI) gene. Specimens collected from each sampling site were labeled as BO1, BO2, BO3 (Bolaang Mongondow District) and BMU1, BMU2, BMU3 (North Bolaang Mongondow). The COI gene fragments obtained were 655 base pairs in length. BLAST analysis of the sequences revealed that the six samples belong to three species: Sicyopterus pugnans, Sicyopterus cynocephalus, and Awaous ocellaris, with similarity levels ranging from 99.55 to 100%. These findings confirm the presence of at least three genetically distinct Nike fish species in the coastal waters of Bolaang Mongondow Raya. The results contribute to a better understanding of local goby biodiversity and highlight the importance of incorporating molecular tools into fisheries management and conservation strategies for sustaining this valuable resource.