Two new trans-Andean species of Imparfinis Eigenmann & Norris, 1900 (Siluriformes: Heptapteridae) from Colombia

Abstract

Two new species of Imparfinis are described from the trans-Andean region of Colombia. Imparfinis timana is diagnosed by having longer anal fin base , in combination with long adipose fin (24.6-31.3% in SL), 5-6 gill rakers on the first ceratobranchial, 42-43 vertebrae and additional measurements. Imparfinis usmai is distinguished by the combination of first ray of dorsal fin longest, but not projected as a long filament, long adipose fin (21.1-27.0% in SL), maxillary barbel exceeding pelvic-fin base, 39-40 vertebrae, upper caudal-fin lobe pointed and longer than lower lobe, lower lobe rounded, 7-8 gill rakers on the first ceratobranchial, as well as additional measurements. Imparfinis timana is only known from río Guarapas, a small tributary of the upper course of the río Magdalena. Imparfinis usmai is broadly distributed in the upper basin of ríos Cauca and Magdalena, and in the lower Patía river basin. The restricted distribution of I. nemacheir to transAndean drainages (Atrato, Magdalena, and Lago de Maracaibo) is also discussed.Duas novas espécies do gênero Imparfinis são descritas da região transandina da Colômbia. Imparfinis timana é diagnosticada por possuir as nadadeiras adiposa e anal compridas (24,6-31,3% e 12,4-15,5% no CP, respectivamente), 5-6 rastros branquiais no primeiro ceratobranquial, 42-43 vértebras, além de outros caracteres de morfometria. Imparfinis usmai é diferenciada pela combinação do primeiro raio da nadadeira dorsal longo, mas não projetado como um filamento comprido, nadadeira adiposa longa (21,1-27,0% na CP), barbilhões maxilares ultrapassando a base da nadadeira ventral, 39-40 vértebras, lóbulo superior da nadadeira caudal pontiagudo e mais longo que o lóbulo inferior, lóbulo inferior arredondado, 7-8 rastros branquiais no primeiro ceratobranquial e outros caracteres de morfometria. Imparfinis timana é conhecida somente para o rio Guarapas, pequeno tributário da bacia do alto rio Magdalena. Imparfinis usmai é amplamente distribuída nas bacias dos rios Cauca, Magdalena e Patía. A distribuição restrita de I. nemacheir nas bacias da região transandina (Atrato, Magdalena e Lago de Maracaibo) é discutida.

Genetic and Morphometric Evidence for the Recognition of Several Recently Synonymized Species of Trans-AndeanRhamdia(Pisces: Siluriformes: Heptapteridae)

“…About 72 genera in Colombia exhibit a distribution across the Andes, including three others in Heptapteridae (Cetopsorhamdia, Imparfinis, Pimelodella; Maldonado-Ocampo et al, 2008;Villa-Navarro, 2009;Ortega-Lara et al, 2011). The patterns elucidated in this study will provide a foundation for future studies, the totality of which may be able to disentangle finer-scale generalizations of Colombian phylogeography.…”

Cryptic Diversity Between Two Imparfinis Species (Siluriformes, Heptapteridae) by Cytogenetic Analysis and DNA Barcoding

“…10 However, when analyzed chromosomally, no karyotypic differences were observed between I. minutus and the populations of I. mirini, which presented karyomorph A. More significant chromosomal differences were observed between populations of a single species, as seen for karyomorphs A, B, and C of I. mirini ( Table 3).…”

“…[5][6][7] Among the Heptapteridae genera, Imparfinis has been highlighted as taxonomically problematic, accounting for 21 recognized species, 9 of which occur in Brazil. 2,[8][9][10] There have been few cytogenetic studies on this genus, and data are available for only five species: Imparfinis borodini, 11 Imparfinis mirini, 12 Imparfinis hollandi, 13 Imparfinis piperatus, 14 and Imparfinis schubarti. 15 No molecular study has been performed on this group with aims at better establishing evolutionary relationships among its species.…”

Fishes from the Río Alvarado drainage, Upper Río Magdalena Basin, Colombia

“…The Upper Río Magdalena Basin is a region with a relatively well documented ichthyological knowledge in Colombia, which is reflected in the high variety of works published recently, life history studies Zúñiga-Upegui et al 2014), patterns of community structure (Miranda et al 2018;Montoya-Ospina et al 2018;Poveda-Cuellar et al 2018), ecomorphology (Conde-Saldaña et al 2017), exotic species (Albornoz-Garzón and Villa-Navarro 2017), new species descriptions (Ortega-Lara et al 2011;García-Alzate et al 2015;García-Melo et al 2016;Provenzano and Villa-Navarro 2017;Villa-Navarro et al 2017;Albornoz-Garzón et al 2018;García-Melo et al 2018), karyotype descriptions (Conde-Saldaña et al 2018, 2019aIbagón et al 2020), and list of species (Villa-Navarro et al 2006). However, our understanding of basic aspects of the fishes from small drainages in the Upper Magdalena is still limited.…”