Coelacanth vs Common Water Rat

Latimeria chalumnae compared with Hydromys chrysogaster

Key Differences

• Coelacanth is Critically Endangered while Common Water Rat is Least Concern.

Taxonomic Classification

Rank	Coelacanth	Common Water Rat
Kingdom same	Animalia (動物)	Animalia (動物)
Phylum same	Chordata (脊索動物)	Chordata (脊索動物)
Class	Coelacanthi (Coelacanthi)	Mammalia (哺乳類)
Order	Coelacanthiformes (シーラカンス)	Rodentia (ネズミ目)
Family	Latimeriidae	Muridae (Mice & Rats)
Genus	Latimeria	Hydromys
Species	Latimeria chalumnae	Hydromys chrysogaster

Evolutionary Relationship

Coelacanth and Common Water Rat share a common ancestor at the Phylum level: Chordata. (脊索動物)

Conservation Status

Coelacanth

CR — Critically Endangered

Population: ~500

Trend: Decreasing ↓

Common Water Rat

LC — Least Concern

Physical Characteristics

Attribute	Coelacanth	Common Water Rat
Diet	Carnivore	—
Average Lifespan	100 years	—
Average Length	1.8 m	—
Average Weight	80.0 kg	—

Habitat & Geographic Range

Coelacanth

Habitat

Found across multiple habitat types including tropical and subtropical moist broadleaf forests, tropical and subtropical dry broadleaf forests, and tropical and subtropical grasslands and savannas, among 8 distinct biome types spanning the Australasia and Afrotropic and Indomalayan realms. Populations are also found in montane and highland environments at higher elevations.

Range

Distributed across Comoros, Indonesia, Mozambique, and South Africa. Currently classified as Critically Endangered on the IUCN Red List, this species faces significant conservation challenges across its range.

Common Water Rat

Habitat

Typically found in diverse terrestrial and aquatic ecosystems.

Coelacanth

1938年に南アフリカ沖で再発見されるまで6,500万年間絶滅していたと考えられていた生きた化石であるシーラカンスは、2メートル、90kgに達することができます。この種は条鰭類よりも四足動物に近い古代の肉鰭類の系統に属しており、脊椎動物の進化を理解する上で科学的に非常に重要です。インド洋の深い岩礁生息地に生息し、夜行性で体内受精により完全に形成された幼魚を産みます。絶滅危惧IA類（CR）種です。

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.