Resumo

ROMAN-VALENCIA, César; VANEGAS-RIOS, James A.  e  GARCIA G., María D.. Comparative analysis of species of the genus Bryconamericus (Teleostei: Characidae) from Cauca, Magdalena and Ranchería basin rivers in Colombia. Rev. Mex. Biodiv. [online]. 2009, vol.80, n.2, pp.465-482. ISSN 2007-8706.

We reviewed Bryconamericus species from the Cauca, Magdalena and Ranchería rivers in Colombia using type and new specimens. The geographic distribution of B.caucanus was determined. We determined the morphological variation among Bryconamericus species analyzed using meristic, morphometric and osteological characters. The shape of Bryconamericus was analyzed using principal component analysis (PCA), in which measurements were previously processed to correct for the effect of size. The number of vertebrae differentiated B. caucanus from other species of the Magdalena River (37-39 vs.40-42). Bryconamericus arilepis Roman-Valencia et al 2008 differs from other Río Magdalena Bryconamericus in lateral-line scales (50-54 vs. 34-50) and scales between dorsal-fin origin and lateral line (9-11 vs. 5-8). The index of form (IF) built with PCA confirmed the validity of species that share the same shape: B. caucanus Eigenmann 1913 andB. plutarcoi Roman-Valencia 2001, B. tolimae Eigenmann 1913, B. huilae Roman-Valencia 2003, B. arilepis and Bryconamericus sp. nov. Román-Valencia, Vanegas-Ríos and Ruiz-C. in press, and the 2 groups were distinguishable from each other. An ANOVA showed significant differences in pelvic-fin length among species of Bryconamericus (F = 44.7, p = 0000). Anal-fin length was also useful to distinguish the studied species (F = 44.03, p = 0000). Populations of B. caucanus from the lower Río Cauca show greatest similarity in shape with all other populations from Río Ranchería, upper and lower Cauca, and middle Magdalena. Hemibrycon dentatus andH. decurrens are shown to be synonyms of B. caucanus. We reconfirm the existence of 2 new species of Bryconamericus from Río Sogamoso, in the Río Magdalena basin. The geographical distribution of B. caucanus in the Sinú, Ranchería, Cauca and lower Magdalena river basins is established.

Palavras-chave : taxonomy; tropical fish; populations; geographic variation; Bryconamericus.

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