Taxonomy
J. Géry 1965
Currently considered a member of the family Characidae, but are classed by taxonomists as "incertae sedis", which means that their real taxonomic position is uncertain.
Distribution and habitat
Rio Negro basin, Brazil and Colombia;
Rio Itu at Praya Bulufu about 80km upstream of the middle Rio Negro, and Rio Urubani and Rio Demini.
Also found in Rio Muco in Vichada, Colombia.
Water parameters
PH : 3,5 - 5,5
ppm : As low as possible
Breeding
This is a miniature inseminating fish!
Males inseminate females with sperm, rather than fertilising eggs externally like most tetras. Mature males have bony hooks on the fourth unbranched ray and branched rays 1-4 of the anal fin.