DNA barcoding of selected aquarium fishes of Bangladesh

Abstract

The ornamental fish sector is a widespread and global component of international trade, fisheries, aquaculture and development. However, the scope of this sector is vast in our country, but we cannot go ahead because of unconsciousness, lack of knowledge, lack of care of government and no government institutions. This sector should be given priority with extra care because it may a lot of foreign exchange every year by exporting the native ornamental fishes that remain unused in our country. The overall objective of the study was the molecular characterization of selected aquarium fishes to investigate the genetic relationship and to construct the phylogenetic tree among those selected fish species collected from different markets of Dhaka city. In this study, we used a DNA barcoding approach to identify and characterize the selected species. The partial sequence (651bp) of COI (Cytochrome Oxidase Subunit I) gene was analyzed for species identification, and we compared them with reference sequences from different databases (GenBank and BOLD). The mitochondrial cytochrome oxidase I (COI) region of all samples were successfully amplified using PCR. Multiple sequence alignment was done using examined DNA sequences and we got 66.42% similarity among selected species. We found three Orders (Cyprinodontiformes, Cypriniformes and Perciformes) among these five samples which indicate the vast genetic divergence of aquarium fishes. This study also shows the purity of species collected from the markets because the sequences of collected sample were matched with the sequences collected from the GenBank of respected species. Phylogenetic tree was constructed then to show the proper genetic divergence among our experimental species. The findings indicate that DNA barcoding is a powerful technique, accurately identifying samples regardless of sample source. There are several species of aquarium fish in Dhaka city which could not be possible to take under the present study. So, more study is needed to take as many species as possible under investigation to make this sector as a highly profitable business.