Análises moleculares em Ageneiosus (Siluriformes: Auchenipteridae): limites taxonômicos e relações intragenéricas

Abstract

The Amazon Basin remains one of the most extensive, complex and diversifiedfluvial networks of the world. This vast region includes the Orinoco river and the Guyana watersheds, extending from headwaters of the Peruvian Andes tomouth of the Atlantic Ocean.Within Siluriformes, Auchenipteridae family is distributed in the rivers of South America and Panama.Among auchenipterids, Ageneiosusstands out for its diversity of species and wide distribution in these rivers.This study was divided into two topics:the taxonomic delimitation of the species of Ageneiosus and, the phylogenetic position of species within genus.The DNA barcode methodology was used to definegroups within and between speciesthrough the molecular evolution model Kimura-2-parameter (K2P) and the constructNeighbour-Joining tree with 10.000 bootstrap.Eighteen species of Ageneiosus were examinedin total with Auchenipterichthys punctatus and A. longimanus as outgroups.The molecular analysis delimited some of the species and pointed to one complex of species.The inference of phylogenetic relationship within the genus was used based on mitochondrial DNA sequences, COI and ATPase. Phylogenetic relationshipswere investigated using Maximum Likelihood and Bayesian Analysis that provided different evolutionary answers.Those species formeda monophyletic group within Ageneiosus genus and shows complex relationships between species Ageneiosus sp. n. “anal curta”, A. dentatus, A. ucayalensis, A. uranophthalmus, A. sp. n. “projetada” and A. vitattus.There is evidence of the existence of a “clade Tympanopleura” wich represents the group of speciesproposed by Ribeiro (2011).