Trichomycterus argos (Teleostei: Siluriformes: Trichomycteridae), a new species from the Doce River Basin, Eastern Brazil

Abstract

Trichomycterus argos, new species, is described from the Rio Doce basin, situated in the Serra do Brigadeiro (part of theSerra da Mantiqueira) range, southeastern Brazil. The new species is diagnosed by the following characteristics: presenceof six branched rays in the pectoral fin; presence of pelvic fins; tip of nasal barbels extending to posterior border of oper-cular plate of odontodes; presence of a large foramen for ramus lateralis accessorius facialis, visible in dorsal view, in theparietosupraoccipital bone; transverse and straight border between the parietosupraoccipital and frontal bones; pectoral-fin ray prolonged as a filament; body covered with spots that seldom attain eye diameter; pelvic-fin origin placed one or two ocular diameters anterior to dorsal-fin origin; abscence of spots fused as elongated marks on dorsum or flank.

Taxonomical study of Trichomycterus (Siluriformes: Trichomycteridae) from the Ribeira de Iguape River basin reveals a new species recorded in the early 20th century

“…Trichomycterus lauryi is distinguished from all congeners, with the exception of T. argos Lezama et al , , T. dispar , T. gironensis Ardila Rodríguez, , T. hualco Fernández & Vari, , T. manaurensis Ardila Rodríguez, , T. megantoni Fernández & Chuquihuamaní, 2007, T. punctulatus , T. rubiginosus Barbosa & Costa, , T. tetuanensis García‐Melo et al , and T. therma Fernández & Miranda, , by its outer layer of coloration composed of scattered, round, black or dark‐brown spots, smaller or equivalent in size to the circumference of the eye (Figures and ; vs . round spots absent or, if present, either noticeably larger than the circumference of the eye or arranged in longitudinal rows).…”

“…All species examined and incorporated in the molecular analysis (voucher specimens) were identified or validated by comparing with type specimens, original descriptions ( i.e ., Ardila Rodríguez, , ; Barbosa & Costa, ; Fernandez & Chuquihuamaní, ; Fernández & Miranda, ; Fernández & Vari, ; García‐Melo et al , ; Lezama et al , ) and other works with informative data ( i.e ., Bizerril, ; Datovo et al , ; Donin, ; Eigenmann, ; Ferrer & Malabarba, , ; Nascimento et al , ; Terán et al , ; Wosiacki, ; Wosiacki & Garavello, ; Wosiacki & Oyakawa, ), except for the genetic sequences available in GenBank obtained by Nascimento et al . ()***, Ochoa et al .…”

“…All species examined and incorporated in the molecular analysis (voucher specimens) were identified or validated by comparing with type specimens, original descriptions (i.e., Ardila Rodríguez, 2016, 2018; Barbosa & Costa, 2010;Fernandez & Chuquihuamaní, 2007;Fernández & Miranda, 2007;Fernández & Vari, 2009;García-Melo et al, 2016;Lezama et al, 2012) and other works with informative data (i.e., Bizerril, 1994;Datovo et al, 2012;Donin, 2019;Eigenmann, 1918;Ferrer & Malabarba, 2011Nascimento et al, 2017;Terán et al, 2017;Wosiacki, 2005;Wosiacki & Garavello, 2004;Wosiacki & Oyakawa, 2005), except for the genetic sequences available in GenBank obtained by Nascimento et al (2017)***, Ochoa et al (2017aOchoa et al ( , 2017b)* and Pereira et al (2011)**. In these cases, the taxonomic identifications provided by the respective author(s) were adopted and their authorship along the text and in the phylogenetic tree was annotated using asterisks (see earlier).…”

Iterative taxonomy reveals a new species ofTrichomycterusValenciennes 1832 (Siluriformes, Trichomycteridae) widespread in Rio Doce basin: a pseudocryptic ofT. immaculatus

“…T. longibarbatus Costa 1992: MZUSP 43339 (holotype of T. longibarbatus ), 57.8 mm SL; MZUSP 23812 (paratype of T. longibarbatus ), 15, 23.3–47.8 mm SL; (c&s) 2, 36.1–41.4 mm SL. T. argos Lezama et al ., 2012: MZUSP 106274 (paratype of T. argos ), 57–91.2 mm SL. T. nigricans Valenciennes, 1832: MNRJ 17805, 1, 82.1 mm SL.…”

“…That factor has offered some degree of protection against environmental disasters which have most heavily affected the main channel of the Rio Doce. Three species of Trichomycterus have been described from the Rio Doce basin, Trichomycterus alternatus (Eigenmann, 1917), T. argos Lezama et al ., 2012 and T. astromycterus Reis et al ., 2018. Six other species described from other basins have also been reported to occur in the Rio Doce drainage and a number of additional forms still await description (Reis, 2018).…”