Common Metad vs common river snail

Millardia meltada compared with Viviparus viviparus

Taxonomic Classification

Rank	Common Metad	common river snail
Kingdom same	Animalia (Animals)	Animalia (Animals)
Phylum	Chordata (Chordates)	Mollusca (Mollusks)
Class	Mammalia (Mammals)	Gastropoda (Gastropoda)
Order	Rodentia (Rodents)	Architaenioglossa (Architaenioglossa)
Family	Muridae (Mice & Rats)	Viviparidae
Genus	Millardia	Viviparus
Species	Millardia meltada	Viviparus viviparus

Evolutionary Relationship

Common Metad and common river snail share a common ancestor at the Kingdom level: Animalia. (Animals)

Conservation Status

Common Metad

LC — Least Concern

common river snail

LC — Least Concern

Physical Characteristics

Attribute	Common Metad	common river snail
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Common Metad

Habitat

Typically found in diverse terrestrial and aquatic ecosystems.

common river snail

Habitat

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

Range

Found across Europe (7 countries).

Common Metad

The Common Metad (<em>Millardia meltada</em>) is a rodent belonging to the genus <em>Millardia</em> within the family Muridae. As a member of the Old World rats and mice, this species is typically found in diverse terrestrial and aquatic ecosystems across its range. The Common Metad is classified as Least Concern on the IUCN Red List, indicating that its populations are currently stable and not facing immediate extinction risk. Detailed biological traits such as body length, weight, and lifespan have not been widely documented for this species in available records. Its taxonomy places it within the order Rodentia, which encompasses a broad array of gnawing mammals adapted to a wide variety of ecological niches. While specific dietary habits are not well characterized in the available data, members of the genus <em>Millardia</em> are generally understood to be omnivorous, feeding on plant material and invertebrates typical of their habitat. Ongoing monitoring is important for ensuring this species maintains its current conservation standing.

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.