brittlestar vs Common Water Rat

Amphiura filiformis compared with Hydromys chrysogaster

Taxonomic Classification

Rank	brittlestar	Common Water Rat
Kingdom same	Animalia (Animals)	Animalia (Animals)
Phylum	Echinodermata (Echinoderms)	Chordata (Chordates)
Class	Ophiuroidea (Ophiuroidea)	Mammalia (Mammals)
Order	Amphilepidida (Amphilepidida)	Rodentia (Rodents)
Family	Amphiuridae	Muridae (Mice & Rats)
Genus	Amphiura	Hydromys
Species	Amphiura filiformis	Hydromys chrysogaster

Evolutionary Relationship

brittlestar and Common Water Rat share a common ancestor at the Kingdom level: Animalia. (Animals)

Conservation Status

brittlestar

LC — Least Concern

Common Water Rat

LC — Least Concern

Physical Characteristics

Attribute	brittlestar	Common Water Rat
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

brittlestar

Habitat

Native to Europe, inhabiting ecosystems characteristic of the region.

Range

Distributed across Denmark, Norway, and Sweden.

Common Water Rat

Habitat

Typically found in diverse terrestrial and aquatic ecosystems.

brittlestar

The Brittlestar (Amphiura filiformis) is a species in the genus Amphiura. It is currently classified as Least Concern on the IUCN Red List. Native to Europe, inhabiting ecosystems characteristic of the region.

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.