common river snail vs koala

Viviparus viviparus compared with Phascolarctos cinereus

Key Differences

• common river snail is Least Concern while koala is Vulnerable.

Taxonomic Classification

Rank	common river snail	koala
Kingdom same	Animalia (動物)	Animalia (動物)
Phylum	Mollusca (軟体動物)	Chordata (脊索動物)
Class	Gastropoda (腹足綱)	Mammalia (哺乳類)
Order	Architaenioglossa (原始紐舌目)	Diprotodontia (カンガルー目)
Family	Viviparidae	Phascolarctidae (Koalas)
Genus	Viviparus	Phascolarctos (Koalas)
Species	Viviparus viviparus	Phascolarctos cinereus

Evolutionary Relationship

common river snail and koala share a common ancestor at the Kingdom level: Animalia. (動物)

Conservation Status

common river snail

LC — Least Concern

koala

VU — Vulnerable

Population: ~100.0K

Trend: Decreasing ↓

Physical Characteristics

Attribute	common river snail	koala
Diet	—	Herbivore
Average Lifespan	—	15 years
Average Length	—	75 cm
Average Weight	—	10.0 kg

Habitat & Geographic Range

common river snail

Habitat

Typically found in terrestrial and aquatic habitats including forests and freshwater.

Range

Found across Europe (7 countries).

koala

Habitat

Typically found in grasslands, forests, and vegetated habitats.

Range

Found in Australia. Currently classified as Vulnerable on the IUCN Red List, this species faces significant conservation challenges across its range.

common river snail

<em>Viviparus viviparus</em>, the common river snail, is a freshwater gastropod mollusk in the family Viviparidae, order Architaenioglossa. It is distributed across Europe, with populations documented in Austria, Belgium, Bulgaria, Czech Republic, France, Germany, and Hungary, among other countries, typically inhabiting slow-moving and still freshwater bodies including rivers, canals, ponds, and ditches. The species is assessed as Least Concern on the IUCN Red List. Common river snails typically live in soft-sediment benthic habitats, grazing on algae, aquatic plant material, and organic detritus using a radula — a ribbon-like feeding organ characteristic of gastropods. <em>Viviparus viviparus</em> is notable among freshwater mollusks for being viviparous, giving birth to fully formed juvenile snails rather than laying eggs, an adaptation reflected in both the genus and family names. This reproductive strategy typically results in small litter sizes but high juvenile survival compared to egg-laying mollusks. The species plays a role in benthic nutrient cycling and serves as prey for waterfowl, fish, and crayfish. Biological traits such as precise lifespan, body measurements, and population density data vary across localities and remain incompletely documented in comprehensive studies.

koala

オーストラリア東部・南東部を代表する有袋類で、体重は最大15kgに達し、低カロリーのユーカリの葉食から得るエネルギーを節約するために1日最大22時間を睡眠に費やす。他の哺乳類の多くを死に至らしめる有毒なユーカリ成分を処理するために高度に特化しており、解毒に特別に適応した腸内微生物叢を持つ。クラミジア感染症、生息地の伐採、気候変動により個体数が激減し、2022年に絶滅危惧種に指定された。