한국산 전갱이과(Carangidae) 어류의 분자계통분류학적 관계 및 분자동정에 관한 연구

Abstract

The family Carangidae consists of 4 subfamilies, 32 genera, and about 140 species worldwide, whereas there are 3 subfamilies, 16 genera, and 31 species in the Korean waters. Most of these fishes are commercially very important, but their phylogenetic relationships have not been clarified yet. Hence, this study was attempted not only to elucidate molecular phylogenetic relationships among Korean carangid fishes including two newly recorded species in Korea, but also to verify banding patterns of the PCR-RFLP (Polymerase Chain Reaction-Restriction Fragment Length Polymorphism) of the cytochrome oxydase 1 gene for precise identification of carangid eggs and larvae. Two carangid species, newly collected in Korea, were identified as Caranx melampygus and Scomberoides lysan. C. melampygus is distinguishable from the congeneric species of C. sexfasciatusby the following characteristics: no black spot on upper edge of gill cover, the upper jaw not reached posterior margin of eyes, and yellow pectoral fin in juveniles. S. lysanis characterized by having head and upper lip connected with skin tissues, no scute on lateral line, and 4 to 5 pairs of black spots on both sides of lateral line. With DNA sequences representing one nuclear recombination activating gene 2 (Rag2) and two mitochondrial genes, cytochrome b (Cytb) and cytochrome oxidase 1 (CO1), phylogenetic analyses have been performed based on neighbor-joining(NJ), maximum parsimony(MP) and maximum likelihood(ML) method of phylogenetic reconstruction with two outgroup species, Scombrops boops and Leiognathus nuchalis. As a result, in all analyses with the nuclear Rag2, the current subfamilial classification (Carangini, Naucratini, Scomberodini, and Trachinotini) appeared to be acceptable and monophyly of each of the subfamily Carangini and Naucratini was statistically supported with high bootstrap values, but the support of monophyly for each of the subfamily Scomberodini and Trachinotini was nonetheless unresolved due to a single terminal taxon. The analyses with the mitochondrial cytb and CO1 revealed that phylogenetic relationships among subfamilies were not determined because of low statistical support, and the subfamily Carangini was a unique taxon statistically supported as monophyletic subfamily. At the genus level, although the genus Seriola appeared to be a paraphyletic taxon grouping with the genus Naucrates in most of analyses, these relationships were not statistically supported. Monophyly of the five Carangoides species was also rejected because of the frequently changed tree topologies and low bootstrap values. Finally, the first banding patterns of the PCR-RFLP of the CO1 gene could be divided into a total of 13 groups, and the second banding patterns of each group formed one to four different types of DNA bands. Then each of band types could be assigned to 23 different fish species for simple and precise identification of carangid fishes including their eggs and larvae.