common hydra vs Common Water Rat

Hydra vulgaris compared with Hydromys chrysogaster

Key Differences

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

Taxonomic Classification

Rank	common hydra	Common Water Rat
Kingdom same	Animalia (Animals)	Animalia (Animals)
Phylum	Cnidaria (Cnidarians)	Chordata (Chordates)
Class	Hydrozoa (Hydrozoa)	Mammalia (Mammals)
Order	Anthoathecata (Anthoathecata)	Rodentia (Rodents)
Family	Hydridae	Muridae (Mice & Rats)
Genus	Hydra	Hydromys
Species	Hydra vulgaris	Hydromys chrysogaster

Evolutionary Relationship

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

Conservation Status

common hydra

NE — Not Evaluated

Common Water Rat

LC — Least Concern

Physical Characteristics

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

Habitat & Geographic Range

common hydra

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.

common hydra

<em>Hydra vulgaris</em>, commonly known as the common hydra, is a small freshwater cnidarian in the family Hydridae. Its conservation status has not been formally evaluated by the IUCN. The species is recorded from Denmark, Norway, and Sweden, with its native range understood to encompass Europe broadly. It typically inhabits slow-moving or still freshwater bodies such as ponds, lakes, and streams, where it attaches to aquatic vegetation or submerged substrates. The common hydra is notable for its remarkable regenerative capabilities and has been the subject of substantial biological research. Diet information for this species is not available in current records. Biological traits of this species remain poorly documented in the scientific literature.

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.