Invasion of African Clarias gariepinus Drives Genetic Erosion of the Indigenous C. batrachus in Bangladesh

The African catfish has been introduced for aquaculture in Bangladesh due to the scarcity of indigenous fingerlings. However, the government of Bangladesh has banned the farming of due to the carnivorous nature of this species. Recently has been reported by fish farmers and consumers in Bangladesh, and unplanned hybridization between native and exotic species has been suspected. This study attempts to know the purity of by analyzing mitochondrial genes. Both directly sequenced and retrieved Cytochrome C Oxidase subunit I (COI) and cytochrome b (Cytb) genes from and were analyzed by MEGA software. The morphologically dissimilar showed the least genetic distance (0.295) from , which provided evidence of hybridization between the two species. Maximum likelihood (ML) phylogenetic trees showed that from Bangladesh did not cluster with of other countries, instead clustered with the exotic . The suspected hybrid formed sister taxa with the exotic . The study corroborates the genetic deterioration of by unplanned hybridization with the invasive . Unplanned hybridization has deleterious consequences; therefore, immediate action is necessary for aquaculture sustainability and biodiversity conservation in Bangladesh.