A new species of Tyttocharax (Characiformes: Characidae: Stevardiinae) from the Güejar river, Orinoco river Basin, Colombia

a new tyttocharax species from the güejar river system, near the macarena mountains in colombia is described. this is the first record for the genus from the orinoco basin. the combination of the following characters distinguish tyttocharax metae from its congeners: presence of bony hooks on the pectoral and caudal-fin rays; bony hooks on the anal-fin rays larger than those on the pelvic-fin rays; pectoral-fin rays i,5-6,i; presence of three unbranched dorsal-fin rays; absence of an adipose fin; four scales rows between the anal-fin origin and the lateral line; and four scale rows between the pelvic-fin and the lateral line. ecological characteristics of the habitat of the new species are also presented.