What is another name for a water rat? - briefly
The Australian water rat (Hydromys chrysogaster) is also called the rakali. It is sometimes referred to as the water mouse.
What is another name for a water rat? - in detail
The term “water rat” is applied to several semiaquatic rodents, each of which carries a distinct common name.
The Australian species Hydromys chrysogaster is widely known as the rakali. It belongs to the family Muridae, inhabits coastal rivers and lakes, and displays webbed hind feet and a dense water‑repellent coat. Its diet consists of fish, crustaceans, and amphibians, and it is the only native Australian mammal that actively hunts underwater.
In South America, members of the genus Nectomys are frequently called water rats. Species such as Nectomys squamipes and Nectomys rattus occupy forest streams and floodplain swamps. They possess elongated tails, partially webbed feet, and a preference for riparian vegetation. Their common name reflects their habit of foraging along riverbanks and in shallow water.
The European water vole (Arvicola amphibius) is sometimes referred to as a water rat, although it is taxonomically distinct from true rats. It resides in slow‑moving rivers, ponds, and marshes across the continent. The animal features a blunt tail, coarse fur, and a herbivorous diet focused on aquatic plants.
Other regional designations include:
- Marsh rat – applied to species like Holochilus sciureus in Central and South America.
- Swamp rat – used for Rattus lutreolus in parts of Australia, though this name overlaps with the rakali.
These alternative labels arise from convergent adaptations to aquatic environments, not from close genetic relationships. The variety of common names underscores the ecological diversity encompassed by the informal label “water rat.”