Molecular phylogeny of Mesonauta Günther, 1862 (Cichliformes: Cichlidae)

Abstract Heroini encompasses Central and South American cichlids. Despite intergeneric relationships within the tribe being well-resolved, species-level relationships within several genera or groups of species remain poorly understood, as well as some genera have never had their monophyly tested through phylogenetic analyses. Here we recover the Mesonauta phylogeny using molecular data from two mitochondrial genes, COX1 and 16S, analyzed under Maximum Likelihood (ML) and Bayesian Inference (BI). Results of ML and BI phylogenies corroborates the monophyly of the genus, comprising six monophyletic groups: Clade (A) comprises Mesonauta karipuna from Amapá Grande River basin as sister to a clade comprising Mesonauta festivus from Guaporé River basin as sister to Mesonauta sp. “Pantanal” from Paraguay River basin, both as sisters to M . acora from Tocantins–Araguaia and Xingu River basins. Clade (B), sister to Clade (A), comprises Mesonauta insignis from Orinoco and Upper Negro River basins and M . egregius from the Orinoco River basin, both as sister to M . mirificus widely distributed in the Amazon River basin and M . guyanae from Amazon/Suriname River basins. However, BI analysis revealed a slightly different topology, which was consistent with the previous species delimitation investigation. Although this previous study of Mesonauta suggested that M . insignis specimens should be grouped with M . egregius , while M . mirificus should be grouped with M . guyanae , we decided to retain the validity of these species, which require further investigation. This first attempt at studying the molecular phylogeny of Mesonauta discusses the advances and difficulties to be overcome, and highlights the intrageneric relationships using molecular data. It also provides data for future studies on the evolution of the group.