Distribution

Eastern Australia. From Cooktown in the north through eastern Queensland and New South Wales, the whole of Victoria and far southeast South Australia to Tasmania.

Biology

The sole species in its family, Ornithorhynchus anatinus is one of the few egg-laying mammals. They are shy, nocturnal animals that hunt for worms, insects and crustaceans on the beds of the rivers in which they live. A distinctive feature is the large, wide, flat horny bill on its snout. Teeth are only present in juvenile animals. The body is covered in thick hair and ends in a short, thick tail. It has sturdy, webbed feet, each with 5 claws. Male animals reach a body length of up to 60 cm and a weight of up to 2 kg; the females are considerably smaller, with a length of up to 40 cm. The male animals have a venom gland under the skin musculature of the thigh. It opens via a venom duct into a hollow, flexible spur on the inside of the hind leg at the level of the ankle. This venom spur is used for defence, and also against other male platypuses. When the animal is in danger, it erects its spurs and clamps its opponent (or, for example, a person's arm) between its hind legs so that the spurs can penetrate far into the skin.

Platypuses live in clear rivers and lakes, from warm coastal rivers to icy mountain streams in Tasmania, to altitudes of up to 1,650 m. They are excellent swimmers. If they sense danger when swimming on the surface of the water, they immediately dive under water. They can stay under water for up to 5 min, where they hunt small animals such as insect or amphibian larvae and crustaceans. Their burrows, which they dig on riverbanks using their strong feet, consist of branching passages several metres in length.

Risk

Accidents are extremely rare and generally only cause strong pain and local swelling. It is primarily fishermen that come into contact with platypuses.

Treatment

Symptomatic.

Literature (biological)

Calaby 1968, Sutherland 1983, Williamson et al. 1996