Molecular phylogenetic analysis of genus Osteobrama Heckel, 1843 and discovery of Osteobrama serrata sp. nov. from North East India.

Genus Osteobrama Heckel is characterized by strongly compressed, fairly deep body with abdominal edge sharp and trenchant entirely or from the pelvic fin base to vent; anal fin long with 14-36 rays, of which 11-13 are branched rays. The fishes of this genus are distributed in Pakistan, India, Bangladesh, Burma, and Yunnan (China). Present study involve six Osteobrama species viz. O. belangeri, O. cotio, O. cunma, O. feae, O. serrata sp. nov., and O. vigorsii. Out of the 655 positions analyzed in the COI sequence dataset, 171 positions (26.1%) were variable, and 151 positions (23%) were parsimoniously informative. The genetic distance between Osteobrama species ranges from 7.10% (between O. cotio and O. serrata sp. nov.) to 22.86% (between O. belangeri and O. feae) for COI sequences and 3.04% (between O. serrata sp. nov. and O. cunma) to 9.89% (between O. serrata sp. nov. and O. belangeri) for 16S sequences. Osteobrama belangeri show very high interspecies K2P distance with all other Osteobrama species for COI and 16S datasets. Best fit models for COI and 16S rRNA dataset were HKY + G + I and K2 + G, respectively. The maximum-likelihood (ML) phylogenetic trees were constructed using the COI and 16S rRNA sequences.