When the first platypus was shipped to Britain from Australia, people thought it was a joke, due to the animal's bizarre appearance - they thought someone had sewn a duck's bill to a mammal's body. Even when it was accepted to be real, people thought it was a bird or a reptile due its to egg-laying abilities.

Meaning of scientific name
Anas is Latin for duck, and -inus means 'like'. Platus is Greek for flat or broad, and pous means foot.

Life span
10 years or more (17 in captivity).

Statistics
Head/body length: males: 45-60cm, females: 39-55cm. Bill length: males: 5.8cm, females: 5.2cm, Tail length: 10.5-15.3cm, females: 8.3-12cm. Weight: males: 1-2.4kg, females: 0.7-1.6kg. There is a large degree of size variation according to area and season.

Physical description
Platypuses have short, dense dark brown fur on their back with a silver to light brown underside and a light patch of fur below the eye and ear groove. They have a flexible bill, which is covered in sensory receptors that respond to electrical and tactile stimuli. Their limbs are short, with large webs on the front feet and partially webbed hind feet. Males have a horny spur connected to a venom duct on their hind limbs, which they use in self-defence, or when fighting rival males for a mate. The venom is strong enough to cause intense pain in humans. They have a broad and flat tail, which as well as aiding swimming acts as a fat storage area. Pouches behind the bill store food.

Distribution
They inhabit east Australia and have been introduced to Kangaroo Island.

Habitat
They live in streams, rivers and lakes.

Diet
Platypus mainly feed on bottom-dwelling invertebrates, but also take the occasional frog, fish, or insect at the water's surface. They use their bill to detect prey and to help them navigate in murky water.

Behaviour
Platypus spend most of their life in the water. They are accomplished swimmers and are able to close their ears, eyes and nostrils when diving. Home ranges vary from less than 1km to over 7km. They burrow into banks - some tunnels can be over 30m long, with nesting chambers. They are generally nocturnal and rest in their burrows during the day.

Reproduction
Platypus mate in July to October. Copulation takes place underwater after the male chases the female and catches her by her tail. The gestation period is not known but is probably about 2-3 weeks. The female lays two (occasionally three) soft-shelled eggs, which are probably incubated for about 10 days (although it is not known for certain). The young suckle from their mother after hatching, and emerge from the burrow in late January to early March.

Conservation status
They are not listed by the 2000 IUCN Red List.

Records
Echidnas and platypuses have the lowest body temperatures of any mammal, around 30 degrees centigrade, which also fluctuates a lot.