Hypseleotris

Hypseleotris is a genus of fishes in the family Eleotridae. Most are from fresh water in Australia and New Guinea, but species in fresh and brackish water are found around islands in the western Indian Ocean, southern and eastern Africa, southern and eastern Asia, and Pacific islands. The largest species reaches a length of 12 cm (4.7 in). They are sometimes seen in the aquarium trade; especially H. compressa. In Australia they are known as carp gudgeons.

The assemblage of species of this genus which occurs in the basin of the Murray-Darling river system is made up of sexually reproducing species and hybrid lineages which consist of a single sex and which have arisen through hybridisation, a process known as hybridogenesis. The single sex species require gametes from the sexual species to reproduce and could be regarded as sexual parasites and in "closed populations" this sexual parasitism can cause the extinction of such populations. It is likely that this reproduction involves androgenesis.