<em>Apistogramma megaptera<em> (Perciformes: Cichlidae), una nueva especie para la cuenca del Orinoco

We describe a new species, Apistogramma megaptera (Perciformes: Cichlidae) that occurs in the upper Orinoco River Basin, in the Inírida, Atabapo and Mavaca rivers of Venezuela and Colombia. This species is characterized by a deep body and a sexual dimorphism expressed in the different shape of the dorsal and caudal fins of males and females, as well as color pattern. Other diagnostic features that differentiate it from other species from Orinoco with crossbars on the caudal fin (Apistogramma iniridae, A. velifera and A. inornata) are: anal fin with marginal black stripe; dorsal fin with a thin marginal black line; infraorbital band wide, its width equal to the pupil; these characters are not present in the above mentioned species. The males reach a larger size (58.7 mm LS) than females (39 mm LS). The pigmentation in the form of crossbars on the tail fin is the character that distinguishes it from other species in the Orinoco River Basin that have immaculate caudal fin (Apistogramma alacrina, A. hoignei, A. hongsloi, A. guttata, A. macmasteri and A. viejita)