Molecular identification and phylogenetic relationship of fishes belonging to the Family Danionidae from Brahmaputra Basin, Assam, Northeast India

The Northeast India, being part of two global biodiversity hotspot namely the Indo-Burma and Eastern Himalayan Hotspots supports a wide variety of rich aquatic biodiversity including fishes. The family Danionidae is a widely diverse group inhabiting the upper colder stretches of river although few are abundant in the lower stretches. The persisting similarity in the morphological appearance and body colouration within the members of this family seeks an integrated method to identify the species correctly.

In the present study, the mt-DNA barcode was generated for correct identification and confirmation of the species. A total of nine mitochondrial cytochrome c oxidase subunit I gene sequences were generated for each species under the study. The pairwise distance values ranged from 0.09 to 9.11% within species and 9.06–32.71% between species. A neighbour-joining tree was constructed based on the Kimura 2 parameter model. Two major groups were observed where Danioninae formed a sister group to the Chedrinae and Rasborinae.

The present study is a preliminary work to document and identify the species under the family Danionidae from Brahmaputra basin, Assam, using molecular tools and establish the phylogenetic relationship.