Authentication of five Barilius species from Indian waters using DNA barcoding

Resumo

Authentic identification of fish species is essential for conserving them as a valuable genetic resource in our environment. DNA barcoding of living beings has become an important and ultimate tool for establishing their molecular identity. Among cyprinids, Barilius is an important genus having nearly 23 species in Indian region whose morphological identification is often difficult due to minute differences in their features. Five species collected from Indian waters and primarily identified as Opsarius bakeri (syn. Barilius bakeri), B. gatensis, B. vagra, B. bendelisis and B. ngawa were authenticated by their DNA barcoding based on mitochondrial COI gene sequences. Five individuals of each species were taken for barcode preparation by COI gene sequencing which yielded one barcode for B. ngawa, two barcodes each for O. bakeri, B. gatensis, B. bendelisis and three barcodes for B. vagra. The order of inter and intra-specific variation was estimated to know a preliminary status of variation prevailing in these cold stream fish species significant for evolution and conservation of these valued species of our ichthyofauna. Average variation within genera was found to be 13.6% with intra-specific variation ranging from 0.0% (B. ngawa) to 0.6% (B. gatensis). These distance data are in the same order found by various researchers globally using COI barcode sequences in different fish species. Phylogenetic relatedness among Barilius species and some other cyprinids validate their status of individual species as established by conventional taxonomy.