Paedocypris progenetica is a species of cyprinid fish endemic to Sumatra (Indonesia) where it is found in peat swamps and blackwater streams. It is the smallest known fish in the world, with females reaching a maximum size of 10.3 mm (0.41 in), males 9.8 mm (0.39 in) and the smallest known mature specimen, a female, measuring only 7.9 mm (0.31 in). It held the record for the smallest known vertebrate until the frog Paedophryne amauensis was formally described in January 2012.