DNA Barcoding And Genetic Diversity Analysis Of Three Species Of Mudskippers Along The Coast Of Southeast China

As an indispensible method in molecular biology, DNA barcoding is able to identify species rapidly and has attracted a lot of attention in the field of animal taxonomy and ecology. The sequences of the mitochondrial cytochrome C oxidase subunit I (COI) and NADH dehydrogenase subunit II (ND2) were sequenced. With the conbined sequence of two genes, samples of Boleophthalmus pectinirostris, Periophthalmus modestus and Scartelaos histophorus collected from six different localities along the coast of Southeast China are detected for genetic analyse.All three makers shows that the nucleotide diversity was much lower than haplotype diversity. There was a significant interspecific genetic gap among three species of mudskippers,but there was no significant subdivision between geographic populations of S. histophorus or B. pectinirostris. Gene flow among the geographic populations was considerably high of COI gene(Nm>4). However, ND2and conbined genes show a moderate differentiation amone six localities. Phylogenetic trees (NJ, MP, and Bayes) demonstrated that the haplotypes belonging to the same species formed a monophyletic clade; haplotypes of B. pectinirostris and S. histophorus, appeared to disordered distribution pattern and cannot form corresponding geographic clusters. The results manifest the promotion of preserving genetic diversity of three mudskippers and their populations. The results also indicate that as a DNA barcoding, COI gene is able to identify species at the species level but not at the population level. ND2gene is better toword the young species because its higher successful rate. Conbined gene has no special advantages other than serving for network analyse.