The ACT has five species of freshwater crayfish in its rivers. The Murray River crayfish has an ornate spiny abdomen with four rows of spines, and two large white claws. Males have larger claws than females, and females have a fatter abdomen. The thorax has two rows of small spines. It can grow its carapace to 150 mm long. It is found in the Murrumbidgee, Cotter and Paddys Rivers, but has been exterminated by overfishing and heavy metal poisoning in the Molonglo River. A red crayfish Euastacus nobilis crassus is found in the swamps on Mount Franklin and Mount Gingera. The 5 cm long Engaeus parvulus produces a mound of dirt around the entrance of its burrow, which has a subterranean chamber more than 30 cm in diameter, and has its own pool of water at the base. Small pools of water hold the tiny Daphnia, copepods and ostracods.