Description

SINGLE PAPER

Volume 14, Issue 4 – 15 October 2008

Wilson J. E. M. Costa: Redescription of Rivulus santensis (Teleostei: Cyprinodontiformes: Rivulidae), a killifish species from the Atlantic forest of southeastern Brazil, pp. 195-202

Abstract

Rivulus santensis, a poorly known killifish species from the Atlantic forest of southeastern Brazil, is redescribed. It is endemic to an area encompassing the middle and lower rio Ribeira de Iguape basin and smaller coastal river basins of São Paulo and Paraná states. Rivulus santensis is distinguished from all other species of the genus by the colour pattern of the caudal fin in males, in which there is a dark grey to black stripe on the dorsal margin of the fin, and another stripe that is similar but distinctively wider on the ventral margin. It is similar to R. haraldsiolii by having both the snout elongated and slightly pointed in a lateral view. Rivulus santensis differs from R. haraldsiolii in possessing 16 rows of scales around the caudal peduncle and one or two minute contact organs per scale on the middle portion of the flank in males, in contrast to 14 scale rows and two to seven prominent contact organs per scale.