Comparative Analysis of the Systematics and Evolution of the Pampus Genus of Fish (Perciformes: Stromateidae) Based on Osteology, Population Genetics and Complete Mitogenomes

Simple Summary: Pampus is a genus of fish of commercial importance in Asia. This is a comprehensive study on the species delimitation and evolution history of Pampus species. This study integrated information on the skeletal structure and mitochondrial and nuclear molecular data of the genus Pampus to define their species delimitation. Based on these findings, we suggest that P. argenteus and P. echinogaster should be classified as the same species and P. liuorum is speculated to be a valid species. P. cinereus is closely related to P. minor, P. chinensis and P. punctatissimus, but these are different species. Pampus can be divided into six species: P. argenteus, P. punctatissimus, P. cinereus, P. chinensis, P. minor, and P. liuorum. The aim of this study was to resolve the controversies about the phylogeny and taxonomy of Pampus and provide a robust delimitation of Pampus for fisheries management. Pampus is a widespread species of fish in the western Pacific and Indian Oceans that has significant commercial worth. Its evolutionary history and phylogenetics are still poorly understood, and details on its intraspecific taxonomy are debatable, despite some morphological and molecular research. Here, we analyzed this species using skeletal structure data as well as nuclear (S7 gene) and mitochondrial genetic information (COI, D-loop and mitogenomes). We found that the genetic distance between P. argenteus and P. echinogaster was much smaller than that between other Pampus species, and both maximum likelihood and Bayesian phylogenetic trees yielded almost identical tree topologies. An additional and adjacent M repeat was found in the downstream region of the IQM gene cluster of P. argenteus and P. echinogaster, and the trnL2 gene of P. minor was translocated. The genus Pampus experienced early rapid radiation during the Palaeocene with major lineages diversifying within a relatively narrow timescale. Additionally, three different methods were conducted to distinguish the genus Pampus species, proving that P. argenteus and P. echinogaster are the same species, and P. liuorum is speculated to be a valid species. Overall, our study provides new insights not only into the evolutionary history of Pampus but its intraspecific taxonomy as well.