Description of a new catfish genus (Siluriformes, Loricariidae) from the Tocantins River basin in central Brazil, with comments on the historical zoogeography of the new taxon

Author(s)

Silva, Gabriel S. C. ; Roxo, Fabio F. ; Ochoa, Luz E. ; Oliveira, Claudio

• Document type: Journal article
• Source: ZOOKEYS; v. N/A, n. 598, p. 29-pg., 2016-01-01.

Abstract

This study presents the description of a new genus of the catfish subfamily Neoplecostominae from the Tocantins River basin. It can be distinguished from other neoplecostomine genera by the presence of (1) three hypertrophied bicuspid odontodes on the lateral portion of the body (character apparently present in mature males); (2) a large area without odontodes around the snout; (3) a post-dorsal ridge on the caudal peduncle; (4) a straight tooth series in the dentary and premaxillary rows; (5) the absence of abdominal plates; (6) a conspicuous series of enlarged papillae just posterior to the dentary teeth; and (7) caudal peduncle ellipsoid in cross section. We used maximum likelihood and Bayesian methods to estimate a timecalibrated tree with the published data on 116 loricariid species using one nuclear and three mitochondrial genes, and we used parametric biogeographic analyses (DEC and DECj models) to estimate ancestral geographic ranges and to infer the colonization routes of the new genus and the other neoplecostomines in the Tocantins River and the hydrographic systems of southeastern Brazil. Our phylogenetic results indicate that the new genus and species is a sister taxon of all the other members of the Neoplecostominae, originating during the Eocene at 47.5 Mya (32.7-64.5 Mya 95% HPD). The present distribution of the new genus and other neoplecostomines may be the result of a historical connection between the drainage basins of the Paraguay and Parana rivers and the Amazon basin, mainly through headwater captures. (AU)

• FAPESP's process: 12/01622-2 - Analyses of the relationships among the members of the tribe Ancistrini (Siluriformes: Loricariidae) based on DNA sequences
• Grantee: GABRIEL DE SOUZA DA COSTA E SILVA
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 14/06853-8 - Phylogenetic analysis of the relationships and diversification patterns of Trichomycteridae (Teleostei, Siluriformes) using DNA sequences
• Grantee: Luz Eneida Ochoa Orrego
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 15/00691-9 - Harnessing phylogenomic comparative methods to understand the diversification of fishes of the Loricarioidea superfamily
• Grantee: Fábio Fernandes Roxo
• Support Opportunities: Scholarships abroad - Research Internship - Post-doctor
• FAPESP's process: 14/05051-5 - Harnessing phylogenomic comparative methods to understand the diversification of fishes of the superfamily Loricarioidea
• Grantee: Fábio Fernandes Roxo
• Support Opportunities: Scholarships in Brazil - Post-Doctoral