Clymene Dolphin vs Common Water Rat

Stenella clymene compared with Hydromys chrysogaster

Taxonomic Classification

Rank	Clymene Dolphin	Common Water Rat
Kingdom same	Animalia (Animals)	Animalia (Animals)
Phylum same	Chordata (Chordates)	Chordata (Chordates)
Class same	Mammalia (Mammals)	Mammalia (Mammals)
Order	Cetacea (Whales & Dolphins)	Rodentia (Rodents)
Family	Delphinidae (Oceanic Dolphins)	Muridae (Mice & Rats)
Genus	Stenella	Hydromys
Species	Stenella clymene	Hydromys chrysogaster

Evolutionary Relationship

Clymene Dolphin and Common Water Rat share a common ancestor at the Class level: Mammalia. (Mammals)

Conservation Status

Clymene Dolphin

LC — Least Concern

Common Water Rat

LC — Least Concern

Physical Characteristics

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

Habitat & Geographic Range

Clymene Dolphin

Habitat

Typically found in diverse terrestrial and aquatic ecosystems.

Range

Distributed across Norway and Venezuela.

Common Water Rat

Habitat

Typically found in diverse terrestrial and aquatic ecosystems.

Clymene Dolphin

The Clymene dolphin, Stenella clymene, is a small cetacean endemic to the tropical and subtropical waters of the Atlantic Ocean, ranging from the Gulf of Mexico and Caribbean Sea south along both the western and eastern Atlantic margins to approximately 20 degrees south latitude. Often called the short-snouted spinner dolphin, it is the only known naturally occurring cetacean hybrid species, believed to have originated through hybridization between the spinner dolphin (S. longirostris) and the striped dolphin (S. coeruleoalba). Clymene dolphins are acrobatic and frequently perform spinning leaps similar to but less elaborate than their spinner relatives. They travel in schools typically ranging from 10 to several hundred individuals, sometimes associating with other dolphin species. The species inhabits deep offshore pelagic waters and is rarely observed close to coastlines. It feeds primarily on fish and cephalopods, foraging at night when mesopelagic prey move into shallower waters. Clymene dolphins measure approximately 1.7–2 meters in length and display a distinctive tripartite pattern of dark cape, lighter grey flanks, and white or pale yellow belly. The species is assessed as Least Concern by the IUCN due to its relatively wide range and no evidence of major population-level threats.

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.