Taxonomy & naming
Kottelat, Britz, Tan and Witte described Paedocypris progenetica in 2006 from a peat swamp near Muara Sabak, on the road to Jambi, Sumatra. It sits in the family Paedocyprididae, which the genus anchors, and the specific name refers to progenesis, the retention of juvenile features in the adult.
Morphology
FishBase records a maximum length of 0.5 in SL and notes that the smallest mature female measured only 0.5 in. The adult fish keeps a larval-looking body with a reduced skeleton, which is why it counts among the smallest vertebrates known.
Habitat
FishBase lists it as a freshwater, benthopelagic fish of tropical water in Indonesia. The genus lives in blackwater peat swamps and the streams that drain them, where the water is stained dark and strongly acidic. Specific temperature and hardness readings are not recorded for this species.
Feeding
The diet has not been described. The atlas records no feeding data for this species.
Mating
Mating behaviour has not been described.
Breeding
Reproduction has not been documented in the sources the atlas uses. Captive spawning is not recorded.
In the aquarium
The species is offered by specialist stores, but care records are thin. Fish of this size need a dedicated tank with soft, acidic, tannin-stained water, gentle flow and no larger tankmates. Husbandry beyond that is not recorded for this species.
Conservation
IUCN lists the species as Near Threatened; the assessment year is not given in the FishBase block. Peat swamp forest in Sumatra and Borneo has been drained and burned for plantations, and the habitat loss is the main concern for the genus.