common river snail vs Olive-gray Thomasomys

Viviparus viviparus compared with Thomasomys cinereus

Taxonomic Classification

Rank	common river snail	Olive-gray Thomasomys
Kingdom same	Animalia (Animals)	Animalia (Animals)
Phylum	Mollusca (Mollusks)	Chordata (Chordates)
Class	Gastropoda (Gastropoda)	Mammalia (Mammals)
Order	Architaenioglossa (Architaenioglossa)	Rodentia (Rodents)
Family	Viviparidae	Cricetidae
Genus	Viviparus	Thomasomys
Species	Viviparus viviparus	Thomasomys cinereus

Evolutionary Relationship

common river snail and Olive-gray Thomasomys share a common ancestor at the Kingdom level: Animalia. (Animals)

Conservation Status

common river snail

LC — Least Concern

Olive-gray Thomasomys

LC — Least Concern

Physical Characteristics

Attribute	common river snail	Olive-gray Thomasomys
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

common river snail

Habitat

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

Range

Found across Europe (7 countries).

Olive-gray Thomasomys

Habitat

Typically found in diverse terrestrial and aquatic ecosystems.

Range

Found in Ecuador.

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.