Cave ground-beetle vs Common Water Rat

Trechus pereirai compared with Hydromys chrysogaster

Key Differences

• Cave ground-beetle is Critically Endangered while Common Water Rat is Least Concern.

Taxonomic Classification

Rank	Cave ground-beetle	Common Water Rat
Kingdom same	Animalia (Animals)	Animalia (Animals)
Phylum	Arthropoda (Arthropods)	Chordata (Chordates)
Class	Insecta (Insects)	Mammalia (Mammals)
Order	Coleoptera (Beetles)	Rodentia (Rodents)
Family	Carabidae	Muridae (Mice & Rats)
Genus	Trechus	Hydromys
Species	Trechus pereirai	Hydromys chrysogaster

Evolutionary Relationship

Cave ground-beetle and Common Water Rat share a common ancestor at the Kingdom level: Animalia. (Animals)

Conservation Status

Cave ground-beetle

CR — Critically Endangered

Common Water Rat

LC — Least Concern

Physical Characteristics

Attribute	Cave ground-beetle	Common Water Rat
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Cave ground-beetle

Habitat

Inhabits temperate broadleaf and mixed forests and Mediterranean forests and woodlands within the Palearctic biogeographic realm. Populations are also found in montane and highland environments at higher elevations.

Range

Found in Portugal. Currently classified as Critically Endangered on the IUCN Red List, this species faces significant conservation challenges across its range.

Common Water Rat

Habitat

Typically found in diverse terrestrial and aquatic ecosystems.

Cave ground-beetle

The Cave ground-beetle (Trechus pereirai) is a species in the genus Trechus. It is currently classified as Critically Endangered on the IUCN Red List. Inhabits temperate broadleaf and mixed forests and Mediterranean forests and woodlands within the Palearctic biogeographic realm. Populations are also found in montane and highland environments at higher elevations.

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.