Aspectos taxonómicos de Cetopsorhamdia boquillae y C. nasus (Pisces, Heptapteridae), con anotaciones sobre su ecología en la cuenca alta de los ríos Magdalena y Cauca, Colombia

Abstract

Taxonomic aspects of Cetopsorhamdia boquillae and C. nasus (Pisces, Heptapteridae), with annotations on their ecology from Magdalena and Cauca rivers upper basin, Colombia

Ataxonomic analysis of Cetopsorhamdia boquillae and Cetopsorhamdia nasus from the Magdalena and Cauca river basin in Colombia is reported here based on fresh topotypical materials. Cetopsorhamdia boquillae can be differentiated from its congener by the color pattern, mainly concerning three dark lines: one on the supraoccipital bone, another at the dorsal fin base and a third at the caudal fin base. The pterygiophore of the dorsal fin first ray is inserted anterior to the ninth vertebra. C. nasus is readily distinguished from its congener by its lack of supraneural spines, fewer than 60 premaxilla teeth, the posterior edge of mesethmoid, and orbitonasal lamina joined by a cartilage band, and the shape of the frontal canal. Cetopsorhamdia boquillae can be distinguished from C. nasus by the length of the adipose-dorsal fin base (statistically significant) (F = 21, P = 0.05), the number of principal unbranched anal rays (5-6 in C. boquillae, 4 in C. nasus), and fewer vertebrae (36 in C. boquillae, 39 in C. nasus). Chemical, physical and ecological data are included to characterize the species habitats.