Collared Worm Salamander vs Common Water Rat

Oedipina collaris compared with Hydromys chrysogaster

Key Differences

• Collared Worm Salamander is Data Deficient while Common Water Rat is Least Concern.

Taxonomic Classification

Rank	Collared Worm Salamander	Common Water Rat
Kingdom same	Animalia (Animals)	Animalia (Animals)
Phylum same	Chordata (Chordates)	Chordata (Chordates)
Class	Amphibia (Amphibians)	Mammalia (Mammals)
Order	Caudata (Caudata)	Rodentia (Rodents)
Family	Plethodontidae	Muridae (Mice & Rats)
Genus	Oedipina	Hydromys
Species	Oedipina collaris	Hydromys chrysogaster

Evolutionary Relationship

Collared Worm Salamander and Common Water Rat share a common ancestor at the Phylum level: Chordata. (Chordates)

Conservation Status

Collared Worm Salamander

DD — Data Deficient

Common Water Rat

LC — Least Concern

Physical Characteristics

Attribute	Collared Worm Salamander	Common Water Rat
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Collared Worm Salamander

Habitat

Typically found in freshwater habitats, moist forests, and wetlands.

Common Water Rat

Habitat

Typically found in diverse terrestrial and aquatic ecosystems.

Collared Worm Salamander

The Collared Worm Salamander, known scientifically as <em>Oedipina collaris</em>, is a slender, elongated salamander belonging to the family Plethodontidae, the lungless salamanders. <em>Oedipina collaris</em> is characterised by its worm-like body form, extremely elongated trunk with many vertebrae, short limbs, and a long tail — morphological features that adapt the species for a burrowing or semi-fossorial lifestyle. As a plethodontid salamander, <em>Oedipina collaris</em> lacks lungs and respires entirely through its moist skin, making it highly dependent on humid environments. The species inhabits freshwater habitats, moist forests, and wetlands. Detailed biological traits including typical lifespan, body length, and weight are poorly documented for this species in available literature. The Collared Worm Salamander is currently assessed as Data Deficient on the IUCN Red List, indicating that insufficient information is available to determine its conservation status accurately, and further research on the species' distribution and population trends is required.

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.