A new species of Chaetostoma, an armored catfish (Siluriformes: Loricariidae), from the río Marañón drainage, Amazon basin, Peru

Abstract

A new species of Chaetostoma was found in mountain tributaries of the río Marañon, Peru. The new species differs from all described congeners by having a tuft of odontodes, surrounded by naked skin, in the middle of each trunk lateral dermal plate, and in bearing more than 20 hypertrophied evertible odontodes on three cheek plates vs. evenly distributed odontodes on the whole surface of each dermal plate, and in bearing fewer than 20 hypertrophied evertible odontodes on three cheek plates in all other Chaetostoma species. The new species resembles two Cordylancistrus species in the presence of a tuft of odontodes in the middle of each trunk lateral dermal plate, but it exhibits a naked snout (vs. snout covered with plates in Cordylancistrus) and one uniquely derived character present in some species of Chaetostoma -a short, slender fourth branchiostegal ray.Una distintiva especie de Chaetostoma fue descubierta en los tributarios de montaña del río Marañón, Perú. La nueva especie se diferencia de todas las otras especies de Chaetostoma descritas por tener un mechón de odontodes, rodeado por piel desnuda, en el medio de cada placa dermal lateral del tronco, y más de 20 odontodes hipertrofiados evertibles en tres placas de la mejilla, en contraste con los odontodes distribuidos de forma homogénea sobre toda la superficie de cada placa dermal lateral del tronco, y menos de 20 odontodes hipertrofiados evertibles en tres placas de la mejilla en las demás especies. La nueva especie se parece a dos especies de Cordylancistrus que exhiben un mechón de odontodes en el medio de cada placa dermal lateral del tronco, pero exhibe un hocico desnudo (vs. hocico cubierto por placas en Cordylancistrus) y un caracter derivado único de algunas especies de Chaetostoma -el cuarto radio branquiostego corto y delgado.

A new species of Chaetostoma (Siluriformes: Loricariidae) from the Orinoco basin with comments on Amazonian species of the genus in Colombia

“…C. chimu differs from congeners except C. anale , Chaetostoma bifurcum Lujan et al ., 2015a, C. breve , C. brevilabiatum , Chaetostoma changae Salcedo, 2006, Chaetostoma daidalmatos Salcedo, 2006, Chaetostoma dermorhynchum Boulenger, 1887, Chaetostoma dupouii Fernández‐Yépez, 1945, C. fischeri Steindachner, 1879, C. formosae , Chaetostoma floridablancaense , Chaetostoma guairense Steindachner, 1881, Chaetostoma jegui Rapp Py‐Daniel, 1991, C. joropo , C. lepturum Regan, 1912, C. leucomelas , Chaetostoma lineopunctatum Eigenmann & Allen, 1942, C. marginatum , C. milesi , C. niveum , C. palmeri , C. patiae , C. paucispinis , Chaetostoma pearsei Eigenmann, 1920, Chaetostoma stannii Lütken, 1874, Chaetostoma stroumpoulos Salcedo, 2006, C. tachiraense , Chaetostoma taczanowskii Steindachner, 1882, C. thomsoni , Chaetostoma trimaculineum Lujan et al ., 2015a, C. vagum (new synonym of C. anale , see below), Chaetostoma vasquezi Lasso & Provenzano, 1998, Chaetostoma venezuelae (Schultz, 1944) and Chaetostoma yurubiense Ceas & Page, 1996, by having curved cheek odontodes ( vs . cheek odontodes straight through most or all of odontode length in C. anomalum , Chaetostoma branickii Steindachner, 1881, Chaetostoma carrioni (Norman, 1935), C. dorsale , Chaetostoma lexa (Salcedo, 2013), Chaetostoma loborhynchos Tschudi, 1846, Chaetostoma machiquense Fernández‐Yépez & Martín Salazar, 1953, Chaetostoma marmorescens Eigenmann & Allen, 1942, Chaetostoma microps Günther, 1864, Chaetostoma nudirostre Lütken, 1874, C. platyrhynchus , C. sovichthys and Chaetostoma spondylus Salcedo & Ortega, 2015). Chaetostoma chimu further differs from species with straight cheek odontodes in addition to C. guairense and C. pearsei by having a parieto‐supraoccipital excrescence ( vs .…”

“…This genus is one of the most species‐rich of the subfamily Hypostominae along with Hypostomus and Ancistrus , and is in need of taxonomic review with several species of uncertain validity, and a number of undescribed species. Although there have been different works dealing with the taxonomy of Peruvian and Ecuadorian species of Chaetostoma (Lujan et al ., 2015a, 2015c; Salcedo, 2006, 2013; Salcedo et al ., 2011; Salcedo & Ortega, 2015), the status of Colombian and especially Venezuelan species is comparatively poorer, despite modest efforts in the past (Ballen, 2011; Ballen et al ., 2016). Currently 23 species have been documented in Colombia, which represents about half the known diversity in the genus.…”

A new species of the catfish genus Cordylancistrus (Siluriformes, Loricariidae) from the Sierra Nevada de Santa Marta, Colombia

“…Inside the Chaetostoma group, this character is reported also for species of Dolichancistrus (Ballen & Vari, 2012). Species included in Transancistrus have a naked snout border, and species of Chaetostoma have a larger naked surface, mainly towards the dorsoanterior region of snout, in all species of these two genera there is no mention or report of the presence of any kind of odontodes, on naked areas of snout (Rapp Py-Daniel, 1991;Ceas & Page, 1996;Lasso & Provenzano, 1997;Salcedo, 2003Salcedo, , 2006aSalcedo, ,b, 2013Ballen, 2011;Tan & Armbruster, 2012;Salcedo & Ortega, 2015;Lujan, et al 2015c;Ballen, et al 2016). Species of Andeancistrus have a snout totally covered with plates, but lack enlarged odontodes, and A. platycephalus has keels on lateral body plates (Lujan, et al 2015a).…”

“…Therefore, this genus is considered as questionable (Armbruster, 2004(Armbruster, , 2008Lujan, et al 2015b). This result may be reflected in the variability of the external morphological characteristics of recently described new genera and species (Tan & Armbruster, 2012;Salcedo, 2013;Salcedo & Ortega, 2015;Lujan, et al 2015a,c;Provenzano & Villa-Navarro, 2017). Some of these new species exhibit external morphological characteristics such as a naked snout, lateral body plates with spiny keels, longest movable cheek odontodes pass pectoral-fin origin, etc., that may be present in species ascribed to different genera.…”