Neotropical Ichthyology, 10(3):499-518, 2012 Copyright © 2012 Sociedade Brasileira de Ictiologia Review of the Andean armored catfishes of the genus Dolichancistrus Isbrücker (Siluriformes: Loricariidae) Gustavo A. Ballen1 and Richard P. Vari2 The loricariid catfish genus Dolichancistrus is reviewed and four species recognized. Species of Dolichancistrus are distinguished from each other by the degree of development of the pectoral-fin spine, the form of the distal margin of the pelvic fin, the relative size and form of the cheek plates, the pattern of odontodes along the margin of the snout, the presence versus absence of a buccal papilla at the premaxillary symphysis, and the relative lengths of the anal- versus pelvic-spines. Dolichancistrus atratoensis is known from the río Atrato system and the río Cubarradó on the Pacific versant of Colombia; D. carnegiei occurs in the eastern río Magdalena basin in the departments of Boyacá and Santander, Colombia; D. cobrensis inhabits southern tributaries of the Lago Maracaibo basin in Colombia and Venezuela along with some highland rivers of the Cordillera de Mérida in Venezuela draining into the río Orinoco system; and D. fuesslii is known from the Andean piedmont portions of the río Meta basin in the western río Orinoco system. Pseudancistrus pediculatus is considered a junior synonym of Ancistrus fuesslii. Chaetostomus setosus previously assigned to Dolichancistrus, was found to lack features characteristic of its putative congeners and is rather more closely related to other members of Chaetostoma group. Consequently, the species is herein considered as incertae sedis within that group. Dolichancistrus is diagnosed, a key is provided to the members of the genus, and diagnoses and redescriptions are provided for all of the recognized species. Se presenta una revisión del género Dolichancistrus y se reconocen cuatro especies válidas. Las especies de Dolichancistrus se distinguen entre sí a partir del grado de desarrollo de la espina pectoral, la forma del margen distal de la aleta pélvica, el tamaño relativo y la forma de las placas operculares, el patrón de odontoides a lo largo del margen del hocico, la presencia versus ausencia de papila bucal en la sínfisis de las premaxilas, y las longitudes relativas de las espinas anal y pélvicas. Dolichancistrus atratoensis es conocido del sistema del río Atrato y del río Cubarradó sobre la vertiente Pacífico de Colombia; D. carnegiei se encuentra en la vertiente Oriental de la cuenca del río Magdalena en los departamentos de Boyacá y Santander, Colombia; D. cobrensis habita los tributarios sureños de la cuenca del Lago Maracaibo en Colombia y Venezuela así como en algunos ríos de alta montaña de la Cordillera de Mérida en Venezuela drenando hacia el sistema del río Orinoco; y D. fuesslii es conocido de porciones pedimontanas Andinas de la cuenca del río Meta en la región occidental del sistema del río Orinoco. Pseudancistrus pediculatus es considerado un sinónimo junior de Ancistrus fuesslii. Chaetostomus setosus, una especie previamente considerada dentro del género Dolichancistrus, carece de los caracteres diagnósticos de sus congéneres putativos y es considerada como más cercanamente relacionada con otros miembros del grupo Chaetostoma. Consecuentemente, esta especie es considerada como incertae sedis dentro del grupo Chaetostoma. Dolichancistrus es diagnosticado, y se presenta una clave para sus especies, así como diagnosis y redescripciones para todas las especies reconocidas actualmente dentro del género. Key words: Andes, Chaetostoma group, Chaetostomus setosus, Northwestern South America. Introduction the genus was described by Boulenger (1887) as Chaetostomus setosus based on two specimens from an Armored catfishes of the loricariid genus unspecified location in the Andes of Colombia. Steindachner Dolichancistrus Isbrücker are moderate-sized species (1911) subsequently proposed Ancistrus fuesslii from dwelling in Andean piedmont and mid-elevation river eastern Colombia. Soon thereafter Eigenmann (1916, 1917) systems of central and northern Colombia and northwestern described Pseudancistrus carnegiei from the río Magdalena Venezuela. The first-named species eventually assigned to system and P. pediculatus from the upper río Meta system 1Universidad Nacional de Colombia, Grupo Cladistica Profunda y Biogeografia Historica, Instituto de Ciencias Naturales, Apartado Aéreo 7495, Bogotá, Colombia. [email protected]; [email protected] 2National Museum of Natural History, Division of Fishes, Department do Vertebrate Zoology, MRC-159, PO Box 37012, Smithsonian Institution, Washington, D.C. 20013-7012. [email protected] 499 500 Review of the Andean armored catfishes of the genus Dolichancistrus in eastern Colombia. Schultz (1944) continued the use of Católica de Oriente, Rionegro (CP-UCO), Colección de Pseudancistrus Bleeker for species now in Dolichancistrus Zoología de la Universidad del Tolima, Tolima (CZUT-IC), with his description of a new subspecies, Pseudancistrus Field Museum of Natural History, Chicago (FMNH), pediculatus cobrensis, from the río Cobre, a southwestern Instituto Alexander von Humboldt, Villa de Leyva (IAvH- tributary of the Lago Maracaibo system. That pattern of P), Instituto de Ciencias Naturales, Bogotá (ICNMHN), generic assignment was continued by Dahl (1960) who Indiana University (IU, collections now largely at CAS), described P. atratoensis from the río Atrato in northwestern Instituto Nacional de Pesquisas da Amazônia, Manaus Colombia. (INPA), Museo de Biología de la Universidad Central de Dolichancistrus was proposed by Isbrücker (1980) in his Venezuela, Caracas (MBUCV-V), Museo de Ciencias catalogue of the species of the Loricariidae. In that Naturales de UNELLEZ, Guanare (MCNG), Museo de compendium, Isbrücker assigned three species, Historia Natural de La Salle, Bogotá (MLS), Muséum Pseudancistrus atratoensis, P. cobrensis, and P. pediculatus national d’Histoire Naturelle, Paris (MNHN), Museo de la to Dolichancistrus, with P. pediculatus as the type species. Universidad de San Marcos, Lima (MUSM), In a subsequent summary listing of loricariid species, Isbrücker Naturhistorisches Museum, Wien (NMW), National (2001) expanded Dolichancistrus to encompass Ancistrus Museum of Natural History, Smithsonian Institution, fuesslii, Chaetostomus setosus, and Pseudancistrus Washington (USNM), and Zoölogisch Museum, carnegiei, all previously assigned by Isbrücker (1980) to Universiteit van Amsterdam, Amsterdam (ZMA). Lasiancistrus Regan. Isbrücker’s actions were within the Abbreviations in the text are c&s [cleared and stained context of broad taxonomic summaries across the Loricariidae specimens prepared following Taylor & van Dyke (1985) rather than derived from revisionary and/or phylogenetic with modifications], masl (elevation in meters above sea studies focused on Dolichancistrus. Consequently, he neither level) and SL (standard length). In the lists of material delved into the question of the definable species in examined, the museum acronym and catalogue number are Dolichancistrus, nor analyzed their distinguishing features followed by the number of specimens in the lot with the and geographic distributions. Indeed, given the limited parenthetical information indicating the number of available samples of Dolichancistrus it is unlikely that specimens from which counts and measurements were Isbrücker examined material of several nominal species. taken (when different than the total number of specimens) Summaries by Fisch-Muller (2003) and Ferraris (2007) followed and the range of their standard lengths. This is followed Isbrücker (2001) and recognized D. atratoensis, D. carnegiei, by locality information clustered to the degree possible by D. cobrensis, D. fuesslii, D. pediculatus, and D. setosus as geographic proximity. valid. Although the species of Dolichancistrus differ from each Multiple impediments complicated a resolution of the other in various features, they share very similar overall species-level questions in Dolichancistrus. Species were external morphologies of the head, body and unpaired fins. typically described from a limited type series, in one case a In light of that overall uniformity, we provide a general unique holotype and in another instance from two syntypes description for all members of the genus, with individual with inexact type locality information. Diagnoses in the species accounts focusing on details of the head, body, original descriptions of the species assigned to pectoral fin, pelvic fin, odontodes, and pigmentation that Dolichancistrus were either lacking or brief and often differ among species with these data complemented by uninformative and the features purposed to delimit the genus species-specific supplementary information. Dorsal-fin ray were not evaluated across all nominal species. In order to formula includes the dorsal-fin anterior spinelet as an resolve these issues, we examined material including type unbranched fin ray. Specimens displaying secondary sexual series of all nominal species of Dolichancistrus across the dimorphism (primarily in the condition of the genital papilla) generic range. We herein diagnose and redescribe are reported as mature. Osteological nomenclature follows Dolichancistrus, evaluate the recognizable species in the Geerinckx & Adriaens (2006) and Geerinckx et al. (2007) with genus and redescribe each of them. the exception of the use of cheek odontodes rather than cheek spines (e.g., Armbruster, 2008) in order to be Material and Methods