vs Common Water Rat

Chroococcus westii compared with Hydromys chrysogaster

Key Differences

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

Taxonomic Classification

Rank		Common Water Rat
Kingdom	Bacteria (Bacteria)	Animalia (Animals)
Phylum	Cyanobacteria (Cyanobacteria)	Chordata (Chordates)
Class	Cyanobacteriia	Mammalia (Mammals)
Order	Cyanobacteriales	Rodentia (Rodents)
Family	Microcystaceae	Muridae (Mice & Rats)
Genus	Chroococcus	Hydromys
Species	Chroococcus westii	Hydromys chrysogaster

Conservation Status

NE — Not Evaluated

Common Water Rat

LC — Least Concern

Physical Characteristics

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

Habitat & Geographic Range

Habitat

Native to Europe, inhabiting ecosystems characteristic of the region.

Range

Distributed across Norway and Sweden.

Common Water Rat

Habitat

Typically found in diverse terrestrial and aquatic ecosystems.

Chroococcus westii is a species of cyanobacteria in the family Chroococcaceae, likely named in honor of a naturalist or phycologist named West, following the common nineteenth and early twentieth century tradition of naming newly described microorganisms after prominent researchers in the field. The species belongs to a genus of simple, spherical cyanobacteria that occur in pairs or small groups within gelatinous sheaths in freshwater and aquatic environments. Chroococcus westii has been documented from freshwater habitats, contributing to the cyanobacterial diversity of lakes, pools, and associated periphyton communities. Cyanobacteria of the Chroococcaceae are among the foundational components of freshwater microbial ecosystems, contributing to primary production, biofilm formation, and in some lineages, biological nitrogen fixation. The taxonomy of the genus Chroococcus has undergone revision through the application of modern molecular phylogenetic methods, which have revealed that morphologically similar coccoid cyanobacteria can be phylogenetically distant, suggesting the need for further taxonomic work. Chroococcus westii is a relatively obscure species documented primarily in classical phycological literature. It has not received formal IUCN assessment.

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.