Austrolebias luzardoi, a new species of annual fish from the Cuareim river basin, Uruguay (Cyprinodontiformes: Rivulidae)

Abstract

Austrolebias luzardoi sp. n. is described from a temporary pool of the middle section of Cuareim river basin, Departamento de Artigas, northern Uruguay. The new taxon is considered as a member of a group of species morphologically similar, defined by a short predorsal distance, the presence of light dots concentrated in the subdistal area of the dorsal fin, the absence of dark vertical stripes in the body sides of males, and by the presence of differentiated spots in the posterior portion of the caudal peduncle in females. This combination of characters includes the following species A. affinis (Amato, 1986), A. cyaneus (Amato, 1987) and A. periodicus (Costa, 1999). Austrolebias luzardoi sp. n. is distinguished from these species by the color pattern of male body, the dorsal profile of the head, the lowest height of body in relation to its standard length, and the inclination of the suborbital band that is vertical or displaced forward.