Nematolebias, a genus of killifishes uniquely living in temporary pools of south-eastern Brazil, contains two nominal species, N. whitei, a popular aquarium fish, and N. papilliferus, both threatened with extinction and pres- ently distinguishable by male colour patterns. Species limits previously established on the basis of morphological characters were tested using mt-DNA sequences comprising fragments of the mitochondrial genes cytochrome b and cytochrome c oxidase I, taken from 23 specimens representing six populations along the whole geograph- ical distribution of the genus. The analysis supports the recognition of a third species, N. catimbau, new species, from the Saquarema lagoon basin, as an exclusive lineage sister to N. papilliferus, from the Maricá lagoon basin, and N. whitei, from the area encompassing the Araruama lagoon and lower São João river basins, as a basal line- age. The new species is distinguished from congeners by the colour pattern and the relative position of pelvic-fin base, besides 11 unique nucleotide substitutions. The distribution pattern derived from sister taxa inhabiting the Saquarema and Maricá basins is corroborated by a clade of the seasonal genus Notholebias, suggesting a common biogeographical history for the two genera.

This species seems not to difficult in reproduction and can be very productive. It is seen as a good fish for breeders that want to take a chance in breeding annuals.

The way they spawn is, as most annual species do, by diving completely into the substratum of peat- moss or even better coco peat..

This substratum is best placed in a small jar or drinking glass at the bottom, filled at least the depth of the body length of the fishes. In this way the breeder avoid the use of a thick bottomlayer and the pair will enter the jar very quick tolai their eggs.

After 5-6 weeks the fishes are capable to produce there first eggs if food was given sufficiently.

Remarks :

Max. size 0.0 cm.
Dorsal 0,
Anal 0,
D/A 0,
LL scale count (average)0
Pre- dorsal length to % SL – 0 %
Depth to % SL – 0 %