Open AccessNew species of the Corumbataia cuestae group (Siluriformes: Loricariidae) from the Rio Tocantins basin, with comments on its phylogenetic relationships
Author(s) -
Mateus Giovanni Rocha Thimotheo,
Ricardo C. Benine,
Cláudio Oliveira,
Gabriel de Souza da Costa e Silva
Publication year - 2020
Publication title -
neotropical ichthyology/neotropical ichthyology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.593
H-Index - 40
eISSN - 1982-0224
pISSN - 1679-6225
DOI - 10.1590/1982-0224-2020-0060
Subject(s) - biology , loricariidae , snout , anatomy , phylogenetic tree , zoology , catfish , fishery , fish <actinopterygii> , gene , biochemistry
A new species of Corumbataia is described from Rio Maranhão, Rio Tocantins basin, central Brazil. The new species is distinguished from all congeners by the presence of a small, naked area on snout tip; by having the abdomen covered with small platelets forming a shield which reaches the lateral mid-ventral plates; by the anterior profile of the head rounded in dorsal view; by the lower lip not reaching the transversal line of the pectoral girdle; and by the presence of 28 or 29 vertebrae. High genetic divergence in mitochondrial cytochrome c oxidase subunit I (COI) further supports the validity of this new species. Our phylogenetic analysis shows a derived subclade in Corumbataia, herein named as the Corumbataia cuestae group, composed of the new species plus C. cuestae, C. tocantinensis, C. britskii, C. liliai, and C. lucianoi. This group is defined by having a conspicuous crest of hypertrophied odontodes on head; absence of the adipose fin or a single series of platelets at adipose-fin position; and anastomosis of the infraorbital and otic sensory canals over the pterotic-supracleithrum. Here we also restrict the distribution of C. tocantinensis to the Rio Araguaia basin.