Molecular Systematics and Divergence of Tor and Neolissochilus Fishes (Cypriniforms: Cyprinidae) from Southeast Asia and South China

Abstract

In Southeast Asia, mahseer fishes, such as the species of Tor and Neolissochilus, are significant native commercial fish. Their phylogeny and categorization have a convoluted history. In this study, the molecular systematics and divergence of Tor and Neolissochilus fishes from Southeast Asia and South China were examined using the partial or complete sequences of four mitochondrial genes (cytochrome oxidase I, cytochrome b, 16S, and ND4). This study substantiated the monophyly of Tor and supported N. benasi as an independent genus. The result supported T. laterivittatus as a synonym of T. sinensis and T. dongnaiensis as a synonym of T. tambra. In addition, we presented the high diversity and species crypticity of these two taxa in Southeast Asia. The divergent time estimation indicated Tor and Neolissochilus species originated in the early Miocene (about 16.73 Ma), and the divergence of the genus Tor and other species of the genus Neolissochilus began at about 12.86 Ma.