In the 1980s, John Wamsley created a platypus breeding program in Warrawong Sanctuary (see below), which subsequently closed.

Inland, its distribution is not well known. It was considered extinct on the South Australian mainland, with the last sighting recorded at Renmark in 1975.

The platypus is semiaquatic, inhabiting small streams and rivers over an extensive range from the cold highlands of Tasmania and the Australian Alps to the tropical rainforests of coastal Queensland as far north as the base of the Cape York Peninsula.

In 2020, research revealed that platypus fur gives a bluish-green biofluorescent glow in black light.

This contrasts with the small number of electroreceptors in the short-beaked echidna, which dwells in dry environments, while the long-beaked echidna, which lives in moist environments, is intermediate between the other two monotremes.

These features suggest that the platypus has adapted to an aquatic and nocturnal lifestyle, developing its electrosensory system at the cost of its visual system.

Limited acuity is matched by low cortical magnification, a small lateral geniculate nucleus, and a large optic tectum, suggesting that the visual midbrain plays a more important role than the visual cortex, as in some rodents. 

A temporal (ear side) concentration of retinal ganglion cells, important for binocular vision, indicates a vestigial role in predation, though the actual visual acuity is insufficient for such activities. 

The corneal surface and the adjacent surface of the lens is flat, while the posterior surface of the lens is steeply curved, similar to the eyes of other aquatic mammals such as otters and sea-lions.

Although the platypus's eyes are small and not used under water, several features indicate that vision was important for its ancestors.