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.

A new species of suckermouth armored catfish, Cordylancistrus nephelion, is described from seven specimens collected in tributaries of the Tuy River in the Caribbean Sea basin of north-central Venezuela. Cordylancistrus nephelion can be distinguished from the other species assigned to its genus by its unique color pattern, the head and body being marked with irregular white spots. Cordylancistrus nephelion is the third species of the genus described from Venezuela: Cordylancistrus torbesensis (Schultz 1944) from the Mérida mountain range (Cordillera de Mérida), Orinoco River basin; C. perijae Pérez and Provenzano 1996 from Perijá mountain range (Sierra de Perijá), Maracaibo Lake basin; and now C. nephelion from the La Costa mountain range (Cordillera de La Costa). These three species inhabit isolated foothill rivers and have very restricted geographic distributions. The extreme alteration of the Tuy River basin by humans may threaten Cordylancistrus nephelion and the other fish species endemic to the basin with extinction. An artificial key for the species assigned to the genus Cordylancistrus is presented.

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As a part of an assessment of loricariid catfishes inhabiting the Andes of Colombia, specimens belonging to an interesting new species were identified. The new species is described herein, and it is tentatively included in the genus Cordylancistrus. The new species can be easily distinguished among its congeners by the presence of a unique diagnostic character: a fleshy keel or excrescence, black or dark brown, over the posterior tip of supraoccipital. Specimens of the new species were captured in rivers of the Sierra Nevada de Santa Marta and the Sierra de Perijá that drain to the Magdalena River Basin and Caribbean Sea. The occurrence of one species of Cordylancistrus in the Sierra Nevada de Santa Marta could have interesting biogeographic implications for hypotheses related to the geological history of northwestern corner of South America or to the dispersal or vicariance models used to explain biogeographical patterns of related species in Colombia.

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