Genetic divergence among three morphs of Acentrogobius pflaumii (Gobiidae) around Japan and their identification using multiplex haplotype-specific PCR of mitochondrial DNA

Genetic divergence among three morphs of a goby, Acentrogobius pflaumii, was investigated on the basis of sequence variations in a partial section of the mitochondrial cytochrome oxidase subunit I gene. A total of 95 specimens, representing the three morphs, collected almost sympatrically from three sites around the Japanese archipelago, were sequenced, the sequence divergences between the morphs (8.62–15.50%) being much greater than within each morph (0.44–0.57%). In addition, each morph formed a distinct cluster in a neighbor-joining tree. Together with an earlier morphological study, such evidence indicated that each morph clearly represented a distinct species. Based on the determined gene sequences, three morph-specific primers were designed for multiplex haplotype-specific polymerase chain reaction (PCR) to enable quick and easy identification of each morph in future studies, especially for early life ecology given morphological similarities at these stages.