SPECIES: Bidyanus bidyanus — Silver Perch, Bidyan
CLASSIFICATION: Critically endangered
Making its way dangerously onto the critically endangered list is the Silver Perch - which isn't really a 'perch', technically speaking. It's from the Grunter family, and also goes by Silver or Black Bream, or the Aboriginal name Bidyan. The Silver Perch is a medium-sized, schooling freshwater fish. It has a small head, small eyes, small eyes and a beak-like snout. It's usual colouration is dark grey, with a lighter, whitish belly. It's also got a spiny dorsal fin. They're quite the opportunistic feeder, a low-order predator of small aquatic invertebrate.
Once widespread throughout the Murray-Darling river system, since the 1970s it has gone into mysterious, rapid decline and has disappeared from as much as 87% of its former range. Introduced carp (competition for food) and virus are both factors in its decline.
Photo: Ferguson Springs Fish Farm