Alternative name Melanorivulus egens.

Rivulus egens was discovered by W. J. E. M. Costa, B. B. Costa and C. P. Bove on January 12, 2004. Estado de Mato Grosso do Sul: Município de Camapuã, road BR-060, rio São Domingos, upper rio Verde drainage, rio Paraná basin, Brazil.
19o19’26.0”S 53o21’6.8”W, altitude 532 mtr. above sea level.

The species is described in the same paper together with 6 other taxa of the Rivulus genus. These are: Rivulus scalaris, R. cyanopterus, R. dapazi, R. litteratus, R. rutilicaudus and R. rossoi , all members of the punctatus group.

No records are available for the breeding of this species but this will not differ very much with the way other small Rivulus from the R. punctatus group breed.

Remarks :

First of all, life animals are needed for further study of this new species.

Max. size 5.0 cm.
Dorsal 9.5,
Anal 13.5,
D/A 8.5,
LL scale count (average)30.5
Pre- dorsal length to % SL – 77.4 %
Depth to % SL – 22.7%

Costa, W.J.E.M. 2005. Seven new Species of the Killifish Genus Rivulus (Cyprinodontiformes: Tivulidae) from the parana, Paraguay and upper Araguaia River basins, central Brasil. Neotropical Ichthyology, 3 (1). 80, fig. 11.