Comparing genetic Mystacoleucus marginatus and Mystacoleucus padangensis (Cypriniformes: Cyprinidae) based on Cythochrome C Oxidase sub unit I (COI) gene

Mystacoleucus marginatus and M. padangenesis are freshwater fish species that found in Indonesia. Mystacoleucus marginatus is native to Indonesia and M. padangensis is an endemic species to West Sumatra, Indonesia. This study aimed to investigate the relationship between M. marginatus from the Berantas River, East Java, and M. padangensis from Singkarak Lake, West Sumatra based on the Cytochrome Oxidase subunit I (COI) gene. Based on the results, M. marginatus and M. padangenesis have a close genetic distance, with similarity of 99.81%, having difference of 3 nucleotide bases; then they can be identical or synonym. The nucleotide composition in M. marginatus and M. padangensis are almost similar where the percentage of nucleotide composition in M. marginatus is T (28.1%), C (29.2%), A (27.0%) and G (15.8%) and that of M. padangensis is T (28.3%), C (28.8%), A (26.8%) and G (16.2%). Based on phylogenetic tree, both species are closely related in the same cluster. Therefore, it is suggested they are a same species based on the COI gene, but suggesting further research using mitochondrial DNA complex and in-depth morphological analysis.