Common Water Rat vs Javan Mongoose

Hydromys chrysogaster compared with Herpestes javanicus

Key Differences

• Common Water Rat is Least Concern while Javan Mongoose is Not Evaluated.

Taxonomic Classification

Rank	Common Water Rat	Javan Mongoose
Kingdom same	Animalia (Animals)	Animalia (Animals)
Phylum same	Chordata (Chordates)	Chordata (Chordates)
Class same	Mammalia (Mammals)	Mammalia (Mammals)
Order	Rodentia (Rodents)	Carnivora (Carnivorans)
Family	Muridae (Mice & Rats)	Herpestidae
Genus	Hydromys	Herpestes
Species	Hydromys chrysogaster	Herpestes javanicus

Evolutionary Relationship

Common Water Rat and Javan Mongoose share a common ancestor at the Class level: Mammalia. (Mammals)

Conservation Status

Common Water Rat

LC — Least Concern

Javan Mongoose

NE — Not Evaluated

Physical Characteristics

Attribute	Common Water Rat	Javan Mongoose
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Common Water Rat

Habitat

Typically found in diverse terrestrial and aquatic ecosystems.

Javan Mongoose

Habitat

Typically found in diverse terrestrial and aquatic ecosystems.

Range

Widely distributed across Africa (Comoros, Mauritius), Asia (Japan), Europe (4 countries), North America (11 countries), Oceania and the Pacific (Fiji, Micronesia), and South America (Colombia, Guyana).

Common Water Rat

<em>Hydromys chrysogaster</em>, commonly known as the common water rat or rakali, is a semi-aquatic rodent in the family Muridae, native to Australia and New Guinea. It is classified as Least Concern by the IUCN, reflecting its relatively stable population across a broad range of freshwater and estuarine habitats on the Australian continent and associated islands. The species typically inhabits the banks of rivers, lakes, wetlands, and estuaries, where it constructs burrows in streambanks. It is highly adapted for an aquatic lifestyle, with partially webbed hind feet, a flattened head, and a dense waterproof coat. <em>Hydromys chrysogaster</em> is a carnivore, typically feeding on fish, crustaceans, mussels, frogs, and aquatic invertebrates, which it often carries to elevated feeding platforms to consume. The species is nocturnal and crepuscular, most active during early morning and evening hours near the water's edge. Biological traits including average lifespan, body length, and weight remain poorly documented in standardized databases, though adults are generally robust for a rodent, reportedly reaching body lengths of 20–35 cm excluding the tail. Geographic range details for this particular record remain incompletely documented in available data sources. Ecologically, the common water rat is an important apex predator in small-scale freshwater food webs and serves as an indicator species for wetland health in Australian riparian systems.