Variation of Three Species of the Genus Barilius through Geometric Morphometric and Cytochrome C Oxidase Subunit I (COI) Gene Analysis

Abstract

In Bangladesh, species under the genus Barilius, belongs to the Cyprinidae are locally known as koksa, joia and barali. Throughout the world 33 species of the genus are identified, among them 6 species are reported in Bangladesh based on morphological observation. Currently throughout the world, identification of fishes is confirmed through molecular makers, of which Cytochrome C Oxidase Subunit I (COI) is mostly used. Therefore, in this study attempts were taken to confirm the genus Barilius through geometric morphometric analyses and COI based barcoding techniques. The study was conducted from January to December 2017. Samples of B. barila, B. barna and B. bendelisis were collected from Karatoya, Kankra and Atrai rivers. After collection, images of each sample were taken for geometric morphometric analyses and muscle tissues were collected for DNA extraction. The geometric morphometric analyses were done using TPS and PAST softwares. The COI gene was amplified by using 1 set primer followed by electrophoresis, purification and sequencing. The sequences were edited and submitted to the genebank database and analyzed using MEGA6 software. In geometric study, 12 landmarks were digitized, among the 26 principal components (PC), in which the highest Eigenvalue (89.0673) and Percent Variance (91.282%) were found in PC 1. The results of principal component analysis, scatter plot and UPGMA cluster analysis showed that B. bendelisis was clearly distinct from other species. In sequence analysis, a total of 723 sites identified among them 36 (4.98%) were conserved, 668 (92.40%) were variable, 659 (91.15%) were singleton. The estimated Transition/Transversion bias (R) was 0.88. The disparity index test of homogeneity between the sequences showed significant evolution of sequences between B. baria and B. barna. Disparity index per site also showed the values (>0) with larger differences in base composition biases than expected. The highest evolutionary divergence of sequences was found between B. tileo and Osparius shacra (5.803), and the lowest was found between B. barila and B. bendelisis (0.333). The phylogenetic trees based on three methods showed that the taxa were closely related and formed sister taxa. However, the time tree also showed that the studied taxa were evolved from the common ancestor. The findings of the study confirmed the availability of B. barila, B. barna, and B. bendelisis species in Bangladesh, further studies are required to confirm all the available species of the genus using COI gene