Trichomycterus alternatus

materials_examined

CAS 64575 (4 ex.) Paratypes; FMNH 58082 (X-ray) Holotype; FMNH 58083 (62 ex. 2 X-ray) Paratypes; MZUSP 67913 (5 ex.); MZUSP 52541 (4 ex. Alc., 1 ex. C & S);

New species of the catfish genus Trichomycterus (Siluriformes, Trichomycteridae) from the headwaters of the rio São Francisco basin, Brazil.

diagnosis

Diagnosis. Trichomycterus alternatus differs from its congeners of the rio Doce and rio Sao Francisco basins by having seven branchiostegal rays; yellowish to light brown body color; rectangular or rounded sequential dark maculae at the midline of the body, sometimes fused and with a vermicular pattern, or forming a narrow stripe from the post-opercular region to the base of caudal fin; a row of rectangular sequential middorsal maculae, round or fused to maculae of the midlateral of the body; subtruncate caudal fin.

The ichthyofauna of a poorly known area in the middle-southern Espinhaco mountain range, state of Minas Gerais, Brazil: diagnostics and identification keys

distribution

Distribution. Rio Doce basin, in the states of Minas Gerais and Espirito Santo, Brazil.

The ichthyofauna of a poorly known area in the middle-southern Espinhaco mountain range, state of Minas Gerais, Brazil: diagnostics and identification keys

materials_examined

Description of type specimens. Morphometric data for holotype and paratypes in Table 1. See figures 2 and 3 for general external aspect. Body cross-section oval near head, gradually compressed posteriorly towards caudal fin. Body elongate with dorsal and ventral profiles slightly convex on trunk and nearly straight along caudal peduncle. Body depth approximately even along entire body, only slightly decreasing posterior to dorsal-fin origin. * Including full length of first pectoral-fin ray Head depressed, approximately as long as wide. Head width increasing slightly from snout to end of opercle, trapezoid in dorsal view. Mouth subterminal. Upper lip convex, covered with numerous small, short papillae on internal and external surfaces. Premaxillary teeth arranged in three or four well-defined and roughly regular rows. Dentary teeth arranged in one regular outer row, with two additional inner irregular rows near symphysis. Lower lip well developed, convex, with lateral fleshy folds adjacent to base of rictal barbel. Fleshy fold slender than, and half overall size of, lower lip, its insertion anterior to origin of rictal barbel. Anterior nostril closer to upper lip than to anterior m

The type specimens of Trichomycterus alternatus (Eigenmann, 1917) and Trichomycterus zonatus (Eigenmann, 1918), with elements for future revisionary work (Teleostei: Siluriformes: Trichomycteridae)