Ken Lazara described this minute and fragile species and named them after the city Aruana in central Brazil where it was found at 51 03' W; 14 55' S. in temporary pools near the rivers of the middle Araguaia river basin in the states of Tocantins and Goias, Brazil.

Lazara described the species as Cynolebias aruana and Costa replaced it in 1995 to the new formed genus Plesiolebias.

It is closely related to Plesiolebias glaucopterus.

The species was collected by Ruud Wildekamp in 1993 also. He mention the strong resembling to Plesiolebias lacerdai and thinks the species can be a synonyme to it. He further describes the pool it was discovered is a big pool, possible not drying out completely during the dry season.

Plesiolebias aruana lives together with other cyprinodont species like Maretacoara lacortei, Simpsonichthys costai, Pituna compacta and Trigonectes rubrimarginatus. Plesiolebias aruana was at that time the most abundant species in the biotope.

Breeding all members of the Plesiolebias family is for experienced hobbyists only. The eggs need a long incubation period of sometimes 6 to 9 months and are very mall compared to the most other annual fishes. The young fry need absolute infusoria to eat in the fist weeks of their life. Growing to maturity is under good circumstances very quick and within 2 months Plesiolebias is able to reproduce already. This is my expirience but I am aware of other written articals that state this will be more. Slow growth could be triggered by insufficient food in the first weeks of their life.

Production of eggs is abundant but the outcome gives mostly not a good rate in gender and often males are 90 % or more in the offspring what makes it difficult to spread the fish otherwise than by sending eggs. As the members of the genus are also easely stressed it is not easy to send or transport these delicate fishes also.

For every hobbyist that has a special interest in this genus therefore it is a challenge to keep and reproduce them over a longer period of time.

Remarks :

The fry are very small and need to be fed with paramecium or other micro organisms. The use of a bunch of plants in the breeding container also will help the fry to feed for the first days. After one or two weeks fresh artemia can be eaten.

Max. size 3.0 cm.
Dorsal 9.0,
Anal 16.0,
D/A 7.0,
LL scale count (average)24.0
Pre- dorsal length to % SL – 65.0 %
Depth to % SL – 27.0 %

Lazara, K.L. 1991. Cynolebias lacortei, Cynolebias costai and Cynolebias aruana, three new Species of Cloud Fish from Brasil (Teleostei ; Cyprinodontiform ; Rivulidae). Journ. Amer. Killifish Assoc., 23 (5), (1991): 147, figs. 4-5.

Costa, W.J.E.M. 2007. Taxonomy of the plesiolebiasine killifish genera Pituna, Plesiolebias and Maratecoara (teleostei: Cyprinodontiformes: Rivulidae), with descriptions of nine new species. Zootaxa 1410: 25-27, figs. 16-17.