The Empire Gudgeon is a small freshwater species. The species is known from Australia and Papua New Guinea. In Australia it occurs primarily in in the lower reaches of coastal drainages from central Western Australia, around the tropical north, and south on the east coast to southern New South Wales.
Normally found in still or flowing waters with juveniles occurring in fast flowing water and often schooling in estuaries. Tolerant of salinity levels equal to sea water and temperatures up to 35°C.
In the Northern Agricultural Region the Empire Gudgeon is found in the Irwin, Greenough, Chapman and Murchison Rivers. The map below shows the Australian distribution of the species based on public sightings and specimens in Australian Museums.
Males are vibrantly coloured during the breeding season. Females are brown to golden and whitish below. In the breeding season males become bright orange-red on the head and belly. The dorsal and anal fins become bright red-orange basally and with a dark sub-marginal stripe and lighter margins. The species grows to about 12 cm in length.
Diet includes a range of aquatic invertebrates such as cladocerans and insect larvae but also grazes on algae and detritus. Normally spawns in the warmer months with eggs being laid on rock, weed or sand and guarded by the male.
Information source: https://australianmuseum.net.au/empire-gudgeon-hypseleotris-compressa and Atlas of Living Australia.