A new species of Chaetostoma Tschudi (Siluriformes: Loricariidae) from Colombia with a definition of the C. anale species group

Abstract

Chaetostoma formosae sp. nov. is described from piedmont tributaries of the upper río Meta on the Cordillera Oriental in Colombia. The new species is distinguished from its congeners by the presence of an elongate unbranched anal-fin ray with two posterior dermal ridges in mature males, the presence of strongly recurved cheek odontodes, the presence of a parieto-supraoccipital dermal keel, the posterior margin of the pelvic-fin strongly projected and angulate in shape in mature males, and by details of coloration. The new species belongs to an informal monophyletic group herein called the Chaetostoma anale species group, along with two additional species, C. anale and C. jegui, from Colombia and Brazil respectively, based on an apomorphic modification of the anal fin in mature males.

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).…”

“…Starting with the diagnostic character of the species among congeners, the presence of a fleshy keel on posterior tip of supraoccipital. This character is present in some species of Chaetostoma (Rapp Py- Daniel, 1991;Ceas & Page, 1996;Lasso & Provenzano, 1997;Ballen, 2011;Ballen, et al 2016). However, the new species is not included in Chaetostoma because other external characteristics (see below) that are traditionally used to recognize species of this genus match partially or not at all.…”

Fishes of the Cusiana River (Meta River basin, Colombia), with an identification key to its species

“…The documentation of the ichthyofauna in cis-Andean Colombian sub-basins has been increasing during the last decade, but new records and species can likely still be found in areas previously thought to be well-sampled (e.g., Ballen 2011, Vanegas-Ríos et al 2015, Ballen et al 2016a, 2016b, Burns et al 2017, García-Alzate et al 2017). Most of the sampling effort has been carried out in the piedmont and lowland areas in the Cusiana as well as in other sub-basins, and exploration of High Andean areas could lead to the discovery of local endemic species at the basin scale that usually are underestimated (Carvajal-Quintero et al 2015).…”

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

“…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.…”

“…Currently 23 species have been documented in Colombia, which represents about half the known diversity in the genus. The species Chaetostoma aburrense (Posada, 1909), Chaetostoma anomalum Regan, 1903, Chaetostoma brevilabiatum Dahl, 1942, Chaetostoma fischeri Steindachner, 1879, Chaetostoma floridablancaensis Ardila Rodríguez, 2013, Chaetostoma lepturum Regan, 1912, Chaetostoma leucomelas Eigenmann, 1918, Chaetostoma marginatum Regan, 1904, Chaetostoma milesi Fowler, 1941, Chaetostoma niveum Fowler, 1944, Chaetostoma palmeri Regan, 1912, Chaetostoma patiae Fowler, 1945, Chaetostoma paucispinis Regan, 1912, Chaetostoma sovichthys Schultz, 1944, Chaetostoma tachiraense Schultz, 1944 and Chaetostoma thomsoni Regan, 1904 are found west of the Andes in trans‐Andean drainages (Maracaibo, Magdalena‐Cauca, Atrato and Pacific Coast, and Patia), whereas Chaetostoma anale (Fowler, 1943), Chaetostoma breve Regan, 1904, Chaetostoma dorsale Eigenmann, 1922, Chaetostoma formosae Ballen, 2011, Chaetostoma joropo Ballen et al ., 2016, Chaetostoma platyrhynchus (Fowler, 1943) and Chaetostoma vagum Fowler, 1943 are found east of the Andes in cis‐Andean drainages (Amazon and Orinoco) (Ballen, 2011; Ballen et al ., 2016; Chindoy et al ., 2019).…”