Blacktail spurdog vs Common Water Rat

Squalus melanurus compared with Hydromys chrysogaster

Key Differences

• Blacktail spurdog is Data Deficient while Common Water Rat is Least Concern.

Taxonomic Classification

Rank	Blacktail spurdog	Common Water Rat
Kingdom same	Animalia (Animals)	Animalia (Animals)
Phylum same	Chordata (Chordates)	Chordata (Chordates)
Class	Elasmobranchii	Mammalia (Mammals)
Order	Squaliformes (Squaliformes)	Rodentia (Rodents)
Family	Squalidae	Muridae (Mice & Rats)
Genus	Squalus	Hydromys
Species	Squalus melanurus	Hydromys chrysogaster

Evolutionary Relationship

Blacktail spurdog and Common Water Rat share a common ancestor at the Phylum level: Chordata. (Chordates)

Conservation Status

Blacktail spurdog

DD — Data Deficient

Common Water Rat

LC — Least Concern

Physical Characteristics

Attribute	Blacktail spurdog	Common Water Rat
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Blacktail spurdog

Common Water Rat

Habitat

Typically found in diverse terrestrial and aquatic ecosystems.

Blacktail spurdog

The Blacktail spurdog (Squalus melanurus) is a species in the genus Squalus. It is currently classified as Data Deficient on the IUCN Red List.

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.