Common ray vs Common Water Rat

Telatrygon biasa compared with Hydromys chrysogaster

Key Differences

• Common ray is Vulnerable while Common Water Rat is Least Concern.

Taxonomic Classification

Rank	Common ray	Common Water Rat
Kingdom same	Animalia (Animals)	Animalia (Animals)
Phylum same	Chordata (Chordates)	Chordata (Chordates)
Class	Elasmobranchii	Mammalia (Mammals)
Order	Myliobatiformes (Myliobatiformes)	Rodentia (Rodents)
Family	Dasyatidae	Muridae (Mice & Rats)
Genus	Telatrygon	Hydromys
Species	Telatrygon biasa	Hydromys chrysogaster

Evolutionary Relationship

Common ray and Common Water Rat share a common ancestor at the Phylum level: Chordata. (Chordates)

Conservation Status

Common ray

VU — Vulnerable

Common Water Rat

LC — Least Concern

Physical Characteristics

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

Habitat & Geographic Range

Common ray

Common Water Rat

Habitat

Typically found in diverse terrestrial and aquatic ecosystems.

Common ray

<em>Telatrygon biasa</em>, the common ray, is a cartilaginous fish in the family Dasyatidae, order Myliobatiformes, belonging to the broader class Chondrichthyes. The species is assessed as Vulnerable on the IUCN Red List, indicating elevated concern over population viability. Common rays are demersal elasmobranchs typically found in shallow coastal and inshore marine habitats, resting on sandy or muddy substrates. Like other dasyatid stingrays, <em>Telatrygon biasa</em> typically feeds on benthic invertebrates including crustaceans, mollusks, and worms, which it detects using electroreceptive ampullae of Lorenzini. It typically moves by undulating its broad pectoral disc, a hallmark locomotion style of stingrays. The vulnerable status of this species likely reflects pressures from bycatch in coastal fisheries and habitat degradation, which are common threats for inshore ray species across the Indo-Pacific region. Biological traits such as lifespan, precise body measurements, and detailed diet composition remain poorly documented for this taxon, and further field research is needed to characterize population structure and reproductive ecology. Conservation measures targeting bycatch reduction in artisanal and commercial fisheries would benefit this species.

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.