Molecular characterization of hilsa shads in Bangladesh using cytochrome C oxidase subunit I (COI) gene

Abstract

The national fish of Bangladesh, Tenualosa ilisha, is a very commercially important species, and it contributes to about 10% of total fish production of the country. In recent times, the production of hilsa has undergone a drastic decline due to overfishing. Fishermen have overfished the species, and mislabled fish have made their way to the market, thereby hurting sales. An investigation was carried out to properly identify hilsa shads based on morphometric, meristic and molecular characteristics. We have morphologically identified three species of hilsa shads; Tenualosa ilisha, Tenualosa toli, and Hilsa kelee, and further validated our results through DNA barcoding. The evolutionary distances indicated that the mean interspecies distance was 25.52%, while the intraspecies distance was 0.22%. Therefore, the study indicates that there are three sepcies of hilsa, and COI is an ideal genetic marker that can be used to identify and confirm the nature of these species.