Cytochrome Oxidase I gene reveals potential cryptic diversity of doublewhip threadfin bream, Nemipterus nematophorus (Bleeker, 1854) in Peninsular Malaysia

Abstract

Genetic variations and differences among three Nemipterus nematophorus populations in Peninsular Malaysia were evaluated based on partial sequence of the mitochondrial Cytochrome Oxidase I gene (654bp). Among the 30 individuals sampled, 12 putative haplotypes were detected, and 58 % (7) of the haplotypes were unique with a high level of haplotype diversity (H= 0.802) and low nucleotide diversity (π = 0.0114). The constructed neighbour joining (NJ) phylogenetic tree based on haplotypes showed two clusters with specimens from Kelantan and Melaka grouped in the same cluster, while Terengganu samples formed an isolated cluster. These two clusters were separated with maximum 2.9 % nucleotide divergence. Analysis of Molecular Variance (AMOVA) revealed a high level of FST value (FST= 0.16; p=0). Pairwise FST value showed significant differences between the Kelantan and Melaka populations from the one in Terengganu. The Terengganu population, although morphologically identical with specimens from Kelantan and Melaka, consisted of a genetically discrete taxon. This study revealed that there is potential cryptic diversity of N. nematophorus in Peninsular Malaysia. These findings are important to provide a scientific framework for sustainable management strategies and conservation of commercially important fishery resources in the region.