vs Common Water Rat

Cobetia pacifica 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	Proteobacteria (Proteobacteria)	Chordata (Chordates)
Class	Gammaproteobacteria (Gammaproteobacteria)	Mammalia (Mammals)
Order	Pseudomonadales (Pseudomonadales)	Rodentia (Rodents)
Family	Halomonadaceae	Muridae (Mice & Rats)
Genus	Cobetia	Hydromys
Species	Cobetia pacifica	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 Asia, inhabiting ecosystems characteristic of the region.

Range

Found in Taiwan.

Common Water Rat

Habitat

Typically found in diverse terrestrial and aquatic ecosystems.

Cobetia pacifica is a halophilic, gram-negative bacterium within the family Halomonadaceae, isolated from Pacific Ocean marine environments. The species epithet 'pacifica' reflects its origin in Pacific coastal and open-ocean habitats, with documented collection records from Taiwanese coastal waters and sediments. As a member of the genus Cobetia, this organism is characterized by its remarkable tolerance and requirement for elevated sodium chloride concentrations, growing optimally in marine-strength and higher salinities. Cobetia pacifica is an aerobic chemoorganotroph capable of metabolizing a diverse array of organic substrates, contributing to carbon cycling in marine ecosystems. The bacterium produces compatible solutes, primarily ectoine and betaine, that stabilize proteins and membranes under osmotic stress. Morphologically, C. pacifica appears as motile rods with polar flagellation, typical of the genus. The Cobetia lineage was separated from the paraphyletic Halomonas genus based on 16S rRNA gene phylogenies and genomic analyses that revealed coherent evolutionary groupings among Pacific-derived halophilic isolates. Members of this genus are of considerable scientific interest for understanding microbial adaptation to saline environments and have potential applications in bioremediation of saline-contaminated sites and industrial fermentation processes where salt-tolerant microorganisms confer operational advantages. The species is not evaluated under IUCN criteria, as conservation assessments are not routinely applied to prokaryotic microorganisms.

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.