Abstract
The golden pompano ranks at the top of production in current China’s marine fish aquaculture; however, there has been long-standing controversy regarding its valid scientific name. Multiple latin names were used simultaneously to refer to golden pompano, such as Trachinotus ovatus, T. blochii, T. mookalee and T. anak. Moreover, two distinct morphological species are regarded as deserving the scientific name T. ovatus. In this study, we employed DNA barcoding to determine which particular species the “golden pompano” represents and to explore the potential synonyms and cryptic species within T. ovatus and its closely related species. We analyzed the DNA barcodes of golden pompano samples from various aquaculture farms in China’s main production regions, as well as most species within the genus Trachinotus. The phylogenetic analyses revealed that all T. ovatus sequences clustered into two divergent clades with a large genetic distance, and the two clades were geographically separated, being from the Indo-west Pacific and the East Atlantic regions, respectively. Based on the type locality information and historical distribution records, we support the validity of the naming of Trachinotus ovatus from the Indo-west Pacific, and the so-called Trachinotus ovatus from the East Atlantic may represent a cryptic species. All the golden pompano samples were clustered into the Indo-west Pacific T. ovatus clade, with a considerably small intragroup genetic distance, which suggests that the golden pompano in China should be identified as the species Trachinotus ovatus. The golden pompano, T. blochii and T. mookalee were completely separated into distinct monophyletic clades in the phylogenetic trees, which indicated that they are different species. The T. anak clustered with the monophyletic clade of Indo-west Pacific T. ovatus and the genetic distance between them was at the intraspecific difference level. This implied that the T. anak might be the junior synonym of T. ovatus. The species delimitations based on the ABGD and bPTP methods are in agreement with the findings from phylogenetic analyses. The above results help to form a consistent viewpoint regarding the naming of the golden pompano and provide new understandings for the taxonomy of the genus Trachinotus.