Genetic population structure of Liza haematocheilus in north-western Pacific detected by amplified fragment length polymorphism markers

Abstract

Several divergent sympatry mtDNA lineages have been described in redlip mullet Liza haematocheilus, and this high inter-lineage divergence raises questions about the taxonomic status of L. haematocheilus lineages in the north-western Pacific. In this study, the amplified fragment length polymorphism technique was employed to examine genetic structure of L. haematocheilus and estimate the level of independence of the different mtDNA lineages in the north-western Pacific. A total of 186 bands were amplified from 91 individuals among 8 populations by 4 primer combinations and the percentage of polymorphic bands was 91.74%. The Unweighted Pair Group Method with Arithmetic Mean tree based on Nei genetic distance revealed two clusters (North Clade and South Clade). Molecular variance analysis and pairwise FST supported the separation of north and south populations of L. haematocheilus in the north-western Pacific. The incongruence between nuclear groups and mitochondrial lineages suggests the three distinct lineages do not represent cryptic species and the presence of divergent mitochondrial lineages in the same sample is a result of secondary contact after an extended period of isolation. The Pleistocene isolation and biological characteristics of species may be responsible for the genetic differentiation of L. haematocheilus.