The mention of the words 'Australian native animal' conjures up visions of koalas kangaroos wallabies and wombats, but mention the words 'Water-rat' and many cringe with visions witnessed only in horror films. In an attempt to encourage a more positive attitude towards this endearing Australian native rodent Hydromys chrysogaster, (kris'-oh'-gaster) or water-rat, the Australian Native Conservation Agency selected a new name for them, 'Rakali', an Aboriginal term for these animals.

The scientific name Hydromys chrysogaster means "water-mouse with golden belly", and though there is considerable variety in coat colour, most recorded suburban animals have dark brown backs and light golden bellies. Rakali occupy fresh water habitats, estuarine environments, and offshore islands throughout Australia and Papua New Guinea, where they are endemic to the region.

The Rakali, with it's unique adaptions to an aquatic way of life, is as uniquely Australian as any of our other native animals.

1. The nose is broad and flattened from above (not from side to side as in R. rattus)

2. Forward pointing nostrils to allow breathing at the surface of the water.

3. High set eyes to allow vision above and below the water surface with equal ease.

4. Small high set ears which can be folded to prevent water from entering the ear canal on diving,

5. A streamlined head and body shape for hydrodynamics.

6. A thick pelt with a dense water-repellent underlayer.

7. Partially webbed hind feet to aid in swimming.

8. The teeth have been adapted to an aquatic diet possessing two cupped molars for crushing food, as opposed to three ridged molars for grinding as seen in other rats.

9. They have a darkly furred long tapering tail ending with the characteristic white tip.

The Rakali population which have made the St.Kilda Breakwater their home has been monitored since October 1997 by volunteers from Earthcare.