Plesiolebiasini Costa

Wilson J. E. M. Costa, 2007, Taxonomy of the plesiolebiasine killifish genera Pituna, Plesiolebias and Maratecoara (Teleostei: Cyprinodontiformes: Rivulidae), with descriptions of nine new species., Zootaxa 1410, pp. 1-41 : 4

Tribe Plesiolebiasini Costa

Diagnosis. Members of the Plesiolebiasini are distinguished from all other rivulids by the following unique features: rostral cartilage with concave anterior edge (Costa, 1998a), short ventral process of the angulo-articular(Costa, 1998a), mesopterygoid and autopalatine not overlapping (Costa, 1998a), first epibranchial bent (Costa, 1995a), and surface of chorion covered by hooks.

Remarks. The present taxonomic accounts focus on the genera Pituna , Plesiolebias , and Maratecoara . The monotypic genus Papiliolebias , endemic to the Chaco, was revised by Costa (1998c). The two species of Stenolebias , S. damascenoi (Costa) and S. bellus Costa , both endemic to the Brazilian Pantanal, are still known only from the few specimens comprising their type series (Costa, 1991b, 1995a, 1995b).

Key to species of the tribe Plesiolebiasini

1a. Scales extending onto anterior 40-50 % of caudal fin in males; pectoral-fin rays 14-15; caudal fin dark brown or dark bluish brown in males; humeral spot metallic blue or metallic green in males...................2

1b. Scales extending onto anterior 25-30 % of caudal fin in males; pectoral-fin rays 11-13; caudal fin never darkly colored in males; humeral spot absent in males...............................................................................3

2a. Dorsal-fin rays 8-11; anal-fin rays 13-16; pelvic-fin rays 7; dorsal and anal fins pointed in males; flank dark brown with oblique rows of small golden spots on flanks in males; distal portion of dorsal fin red in males.......................................................................................................................................... Pituna Costa

2b. Dorsal-fin rays 11-13; anal-fin rays 17-20; pelvic-fin rays 9; dorsal and anal fins rounded in males; flanks golden, with oblique dark brown lines in males; no red pigmentation on dorsal fin in males...................... ........................................................................................................................................ Papiliolebias Costa

3a. Dorsal and anal fins rounded in males; frontal squamation G-patterned.......................... Plesiolebias Costa

3b. Dorsal and anal fins pointed in males; frontal squamation F-patterned.......................................................4

4a. Males with following features: dorsal and anal fins long, tips posteriorly surpassing posterior margin of caudal fin; caudal fin lanceolate, tip with two filamentous rays; opercular membrane with blue iridescence, long, extending onto anterior portion of pectoral fin; flanks metallic blue, with orangish golden spots................................................................................................................................ Maratecoara Costa

4b. Males with following features: dorsal and anal fins short, tips not reaching caudal-fin base; caudal fin rounded and without filaments; opercular membrane hyaline, short, not reaching pectoral-fin base; flanks gray, with faint golden or greenish blue iridescence, and without spots........................... Stenolebias Costa