A new catfish species of the genus Trichomycterus (Siluriformes: Trichomycteridae) from the río Orinoco versant of Páramo de Cruz Verde, Eastern Cordillera of Colombia

Abstract

A new Trichomycterus is described from a highland tributary of the río Meta (Orinoco basin), along the east flank of Páramo de Cruz Verde, Eastern Cordillera of Colombia. The new species is distinguished from most of its congeners by having a reduced posterior cranial fontanel, restricted to the parieto-supraoccipital, cleithrum pierced by several foramina, and an unique combination of four irregular rows of conic teeth in premaxilla and dentary, 13-14 opercular odontodes, 41-43 interopercular odontodes, 6-7 branchiostegal rays, 40 or 41 free vertebrae, 14-18 ribs, first ray of pectoral fin slightly projected as a short filament, 7-8 branched pectoral-fin rays, dorsal-fin origin at same level of pelvic-fin insertion, anal-fin origin posterior to dorsal-fin base, caudal-fin margin slightly rounded, a single upper hypural plate (3+4+5), and coloration pattern consisting in ground color dark brown with a thin mid-lateral dark stripe. Phylogenetic relationships of the new species based on the shared presence of derived features related to posterior cranial fontanel and cleithrum are discussed. The new species is also compared to the only two described species from Andean tributaries of río Orinoco basin.É descrita uma espécie nova de Trichomycterus de um pequeno tributário dos Andes da bacia do río Meta (bacia do río Orinoco), no flanco oriental do Páramo de Cruz Verde na Cordilhera Oriental da Colômbia. A espécie nova distingue-se da maioria de seus congêneres por apresentar uma fontanela craniana posterior reduzida, restrita ao parieto-supraoccipital, cleitro perfurado por vários forames e uma combinação única de quatro fileiras irregulares de dentes cónicos no pré-maxilar e no dentário, 13-14 odontódeos operculares, 41-43 odontódeos interoperculares, 6-7 raios branquiostégios, 40 ou 41 vértebras livres, 14-18 costelas, o primeiro raio da nadadeira peitoral ligeiramente projetado em um curto filamento, 7-8 raios ramificados na nadadeira peitoral, origem da nadadeira dorsal no mesmo nível de inserção das nadadeiras pélvicas, origem da nadadeira anal posterior à base da nadadeira dorsal, margem da nadadeira caudal ligeiramente arredondada, uma única placa hipural superior (3+4+5) e padrão de coloração em um fundo de cor marrom escuro com uma fina listra escura média lateral. As relações filogenéticas da espécie nova com base na presença compartilhada de caracteres derivados relacionados com a fontanela craniana posterior e o cleitro são discutidas. A espécie nova também é comparada com as duas únicas espécies descritas de afluentes dos Andes da bacia do río Orinoco.

Checklist of the freshwater fishes of Colombia: a Darwin Core alternative to the updating problem

“…Most species of Astroblepus have restricted geographic distributions, being limited to portions of single river drainages at elevations above 1000 m (Schaefer et al 2011). A similar scenario is also found for Trichomycterus species, which show high endemism and restricted geographic distributions to headwaters and streams of river systems (Fernández and Vari 2009, Ferrer and Malabarba 2013, DoNascimiento et al 2014b). The taxonomic knowledge of the Colombian species of these genera and their respective geographic distributions is precarious.…”

Living in the waterfalls: A new species of Trichomycterus (Siluriformes: Trichomycteridae) from Tabay stream, Misiones, Argentina

“…Many species of Trichomycterus have uninformative descriptions and are associated to old type material, limiting the applicability of the name only to the types [24]. Currently, the genus contains over 170 species [6], however, its known diversity remains increasing along the recent years.…”

A new troglomorphic species of Trichomycterus (Siluriformes: Trichomycteridae) from north‐eastern Colombia, with proposal of a new Trichomycterus subclade and remarks on some nominal species from Colombia

“…This character was hypothesized by DoNascimiento et al . () as a putative synapomorphy supporting the sister group relationship of T. cachiraensis and T. steindachneri DoNascimiento Prada‐Pedreros & Guerrero‐Kommritz 2014. However, this character has a broader taxonomic distribution than originally thought, and is recorded also in T. ballesterosi , T. gorgona and T. sandovali , and is variably present in T. areolatus and T. migrans ; consequently its phylogenetic significance must be explored in the context of a comprehensive quantitative phylogenetic analysis of Trichomycterinae.…”

“…Other efforts recognizing subgroups of species within Trichomycterus followed (Bizerril, ; Fernández & Vari, ; Bockmann et al ., ; Wosiacki & Garavello, ; Wosiacki, ; Alencar & Costa, ; Fernández & Osinaga, ; Fernández & Miranda, ; Lima et al ., ; Wosiacki & de Pinna, , ; Barbosa & Costa, for T. itatiayae species complex; Barbosa & Costa, for T. travassosi species complex, 2012b; Datovo et al ., ; Fernández & Vari, ; Katz et al ., ; Katz & Barbosa, ; Terán et al ., for T. stawiarski group). Further complicating the recognition of putative monophyletic groups within Trichomycterus , several authors have discussed the morphological evidence suggesting closer phylogenetic relationships of some Trichomycterus species with other trichomycterine genera (DoNascimiento et al ., ; Fernández & Quispe Chuquihuamaní, ; Fernández & Schaefer, ; Mesa et al ., ), and even with other trichomycterid subfamilies (de Pinna, ).…”

“…Colombia, with 56 species, is the country with the second highest diversity of the genus and interestingly, most of these species are distributed in trans‐Andean piedmont and mountainous river systems (DoNascimiento et al ., , ). At the same time, the country is distinguished by a large number of cave inhabiting species ( i.e .…”