Diversity of the family Apogonidae along the northwestern coastline of the South China Sea

To identify species and priority areas for conservation, the DNA barcoding data set (partial sequences of the mitochondrial DNA cytochrome oxidase subunit I gene) of the family Apogonidae along the northwest coast of South China Sea was established. After identifying species by morphology and basic local alignment search tool, 21 cardinalfishes were found, and these species belong to six genera. Among 21 species, there were two first record species (Ostorhinchus nigrocinctus, O. gularis) and one uncertain status species (Ostorhinchus sp.). Average within-genus and within-family genetic distances were 17.12 and 20.55%, respectively. This DNA barcoding of the fish dataset reveals the need for taxonomic revisions of the family Apogonidae. Moreover, our study finds that the size of the specimen distribution of a given species and its intraspecific genetic diversity are positively related. The Beibu Gulf has a higher species diversity and intraspecific diversity than the other geographic regions. These results will help in the management of fisheries and the conservation of the fish biodiversity in South China Sea.