Mitochondrial cytochrome oxidase 1 reveals genetic diversity of the African Snakehead fish Parachanna obscura, Gunther, 1861 from Nigeria's freshwater environment

The study investigated the genetic variation of Parachanna obscura from five rivers (Anambra, Ibbi, Imo, Katsina-Ala and Ogun) in Nigeria using the mitochondrial cytochrome oxidase 1 gene. DNA was extracted from 19, 22, 16, 18 and 21 fin clips per river population, respectively and subjected to polymerase chain reaction. A total of 96 sequences, each with 671 bp were obtained with 38 (5.6%) polymorphic, 27 (3.8%) parsimoniously informative and 659 (98.2%) conserved sites. Mean nucleotide composition was C = 28.07%, T = 29.43%, A = 22.18%, G = 20.32%. A total of 40 haplotypes with 38 unique sequences as well as 24 substitutions with 22 transversions and two transitions were obtained. Nucleotide diversity among populations ranged from 0.00184 to 0.00888 representing Ibbi and Imo, respectively while haplotype diversity ranged from 0.77056 to 0.95000 also, from Ibbi and Imo, respectively. Analyses of molecular variance showed that the intra-population variation accounted for 50.05%. Topology from phylogenetic analyses revealed that P. obscura from Imo River was distinctly different from the rest.