Acrolebias, Costa, 2008

Lanés, Luis Esteban Krause, Volcan, Matheus Vieira & Maltchik, Leonardo, 2021, Two new annual fishes (Cyprinodontiformes: Rivulidae) unexpectedly discovered in the highlands of southern Brazil, Zootaxa 4949 (3), pp. 499-520 : 513

Identification key for the species of the subgenus Acrolebias

1a. Contact organs present on anal fin and opercle of males, preopercular and mandibular series of neuromasts united........ 2

1b. Contact organs absent on anal fin and opercle in males, preopercular and mandibular series of neuromasts separated....... 3

2a. Sides of body dark bluish brown with yellowish golden or light grey narrow vertical bands, prominent contact organs in the flank in males, jaws short, dorsal profile of head nearly convex............................. Austrolebias nubium sp. n. (rio Taquari-Antas, upper rio Jacuí, Lagoa dos Patos basin, Brazil)

2b. Sides of body lilac grey with bluish white vertical bands, discrete contact organs in the flank in males, jaws slightly prognathous, dorsal profile of head slightly concave......................................... Austrolebias botocudo sp. n. (Upper rio Apuaê-Inhandava drainage, rio Uruguay basin, Brazil)

3a. Pelvic fin present, supraorbital series continuous, 27–29 scales in the longitudinal series............ Austrolebias carvalhoi (rio Iguaçu drainage, rio Paraná basin, Brazil)

3b. Absence or extreme reduction of pelvic fin, first three neuromasts of the supraorbital series separated from the remaining neuromasts by an interspace, 31–33 scales in the longitudinal series............................ Austrolebias araucarianus (rio Claro drainage, rio Iguaçu, rio Paraná basin, Brazil)