Molecular Phylogeny of the <i>Opsariichthys</i> Group (Teleostei: Cypriniformes) Based On Complete Mitochondrial Genomes.

Abstract

<b>Shih-Pin Huang, Feng-Yu Wang, and Tzi-Yuan Wang (2017)</b> The complete mitochondrial genomes of 76 species from 43 genera under Cyprinidae <i>sensu lato</i> were collected to reassess the molecular phylogeny of Opsariichthyinae <i>sensu</i> Liao et al. 2011. The mitogenomes of three species, <i>Candidia barbata, Opsariichthys evolans</i>, and <i>Opsariichthys pachycephalus</i>, were newly sequenced. Phylogenetic trees were reconstructed based on 13 concatenated multiple protein-coding genes with two ribosomal RNA genes. The concatenated dataset provided a new perspective on systematics and relationships. Tree topologies show that a monophyletic group containing <i>Parazacco</i>, <i>Candidia</i>, <i>Nipponocypris</i>, <i>Zacco</i>, and <i>Opsariichthys</i> should belong to the <i>Opsariichthys</i> group. In addition, the present results also strongly support that <i>Candidia</i> and <i>Nipponocypris</i> should be regarded as distinct genera within the <i>Opsariichthys</i> group. <i>Aphyocypris</i>, <i>Yaoshanicus</i>, <i>Nicholsicypris</i>, and <i>Pararasbora</i> form a monophyletic group within Xenocyprididae, distinct from the <i>Opsariichthys</i> group. Furthermore, <i>Hemigrammocypris</i> is nested with four species of <i>Metzia</i>, a genus of ex-Cultrinae in Xenocyprididae. In addition, two major types of distinct stripes - longitudinal and vertical - were observed among species of the <i>Opsariichthys</i> group and were highly correlated with molecular phylogenetic relationships. Such types of vertical and longitudinal stripes presented in the <i>Opsariichthys</i> group might have originated in an ancestor species, after which distinct vertical stripes might have been lost among these cyprinids but retained in the <i>Opsariichthys</i> group.