DNA barcoding of some common coastal fishes from Japan and China

Abstract

To determine the species status of some common coastal fishes from Japan and China, 652 bp fragments of cytochrome oxidase subunit I (COI) of 184 individuals of 37 species, 34 genera, 24 families, 7 orders in Japan were sequenced, combined with 143 homologous sequences from Japan and China downloaded from GenBank, a total of 327 sequences of 40 species, 35 genera, 24 families and 7 orders were analyzed. Results showed that the average interspecific genetic distance (6.25%) was about 14.88 times the mean intraspecific distance (0.42%), and 36 species were monophyletic with 97%-99% bootstrap support, supporting their species status. The intraspecies genetic distance of <italic>Lateolabrax</italic> spp. was 3.91%, and formed two clades on the neighboring tree, and the genetic distances between the clades (6.98%) were about 14.2 times those within clades (0.49%), suggesting that <italic>L</italic>. <italic>japonicus</italic> from Japan and <italic>L</italic>. <italic>maculatus</italic> from China might have evolved to two different species, which was consistent with previous studies. The intraspecies genetic distance of <italic>Pennahia argentata</italic> was 2.01%, and it formed two clades with 99% bootstrap support, and the genetic distances between the clades (3.28%) were about 11.3 times those within clades (0.29%), suggesting that <italic>P</italic>. <italic>argentata</italic> from Japan and China might be 2 subspecies or 2 species. <italic>Cleisthenes herzensteini</italic> and <italic>C</italic>. <italic>Pinetorum</italic> were mixed on a clade and both average genetic distances between species (0.32%) and within species (0.23%) was less than 2%, thus it is assumed that there might be misidentification, but the possibility of incomplete lineage sorting can not be ruled out. <italic>Callionymus valenciennei</italic> and <italic>Repomucenus ornatipinnis</italic> clustered into 2 clades, and the average genetic distance between clades (1.97%) was 4.6 times that within clades (0.43%), it is therefore speculated that they might be 2 subspecies or 2 species. Due to the small size of Callionymid fish and significant morphological differences between males and females, the possibility of morphological misidentification can not be ruled out.