A new species of cave catfish, genus Trichomycterus (Siluriformes: Trichomycteridae), from the Magdalena River system, Cordillera Oriental, Colombia

Abstract

A new species of troglomorphic catfish is described from de Gedania Cave, located in the middle Suarez River drainage, Magdalena River system, Colombia. The new species can be distinguished from its congeners by the combination of the following characters: reduction or loss of the cornea, reduction of eyes and skin pigmentation, very long nasal and maxillary barbels (maximum of 160% and 135% of HL, respectively), nine branched pectoral-fin rays, first unbranched ray of the pectoral fin prolonged as a long filament, reaching 80% of pectoral-fin length, anterior cranial fontanel connected with the posterior fontanel through an opening of variable length and width, first dorsal-fin pterygiophore inserted between neural spines of free vertebra 13-14 and free vertebrae 33-34. The presence of troglomorphisms such as regression of the eyes, reduction of skin pigmentation and long barbels suggest the troglobitic status of this species. A comparative analysis with other species of Trichomycterus from epigean and hypogean environments is presented.