Common name: Southern purple-spotted gudgeon
Scientific name: Mogurnda adspersa
Origin: Australia, in the river systems of New South Wales and Queensland, and tributaries of the Darling. This fish is becoming rare and has only been found in NSW once in the past 20 years. Western populations are classed as endangered and wild fish and their habitats are protected. 
Size: Up to 15cm/6", but usually a bit smaller in the aquarium. 
Habitat: Found in slow-moving rivers and still backwaters and creeks, usually among fallen branches, aquatic plants and rocks. 
Water: pH around 7.0; 15-25C/59-77F, GH 10-20.