Genetic Status of Exotic Chinese Carp Hypophthalmichthys molitrix and Hypophthalmichthys nobilis through Mitochondrial Gene Cytochrome C Oxidase Subunit I (COI) in Bangladesh

The use of mitochondrial gene Cytochrome C Oxidase subunit I (mtCOI) has emerged as a promising technique in study of genetic variation and phylogenetic relationship of different group of fishes. This work reports the first example of the study of genetic status of two exotic Chinese carp, silver carp, Hypophthalmichthys molitrix and bighead carp, Hypophthalmichthys nobilis in Bangladesh through the analyses of mtCOI gene. The highest nucleotide sequence divergence occurred between sequenced H. nobilis N3 and reference H. molitrix from India which was 1.208 and the lowest nucleotide divergence occurred in sequenced H. nobilis N1 and sequenced H. molitrix M3 with their reference counterparts from Bangladesh, India and China (0.002). The phylogenetic tree analysis showed that one of the H. nobilis (H. nobilis N3) formed a sister group with H. molitrix M2 with 100% sequence similarities. Otherwise, all sequenced and reference H. molitrix and H. nobilis showed separate clade in the tree. Therefore, we can conclude that the exotic H. molitrix and H. nobilis maintain distinct population status with lower genetic variation. However, we should take essential measures to reduce inbreeding in future.