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 (12.4-15.5% in SL), 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 trans-Andean drainages (Atrato, Magdalena, and Lago de Maracaibo) is also discussed.
Highlights
The genus Imparfinis was described by Eigenmann & Norris (1900), based on the species I. piperatus Eigenmann & Norris, 1900 from southeastern Brazil (São Paulo State)
Imparfinis nemacheir was described from the upper río Magdalena basin, and a single type was designated (Fig. 5b), several specimens were available to the authors, as inferred from ranges of variation in some meristic and morphometric characters and differences in color pattern, indicated in the original description (Eigenmann, 1916)
As we commented before, those Patía and Cauca records belong to I. usmai, whereas the Atrato specimens (FMNH 58130) were in effect identified as I. nemacheir, corroborating the presence of the species in that basin
Summary
The genus Imparfinis was described by Eigenmann & Norris (1900), based on the species I. piperatus Eigenmann & Norris, 1900 from southeastern Brazil (São Paulo State). Two new trans-Andean species of Imparfinis resulted in several different interpretations by authors dealing with the taxonomy and systematics of Heptapteridae, and a continuously changing species composition. The genus includes 19 species (Almirón et al, 2007; Bockmann & Guazelli, 2003; Ferraris, 2007), and is one of the most broadly distributed within the family Heptapteridae, from streams in Costa Rica [Imparfinis lineatus (Bussing, 1970)] to the Paraná and Uruguay river basins in Argentina (I. mishky Almirón, Casciotta, Bechara, Ruíz Díaz, Bruno, D’Ambrosio, Solimano & Soneira, 2007), and to both sides of the Andean cordillera. Explorations conducted in the Cauca and Magdalena drainages in Colombia have resulted in the collection of two species, which fit the most recent diagnoses for Imparfinis offered by Mees (1974) and Mees & Cala (1989), and exhibit all the apomorphic conditions provided by Bockmann (1998) in his phylogenetic diagnosis of Imparfinis. The two species show consistent morphological differences with all described species of Imparfinis, and they are described as new in this paper
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