European otter vs Japanese Weasel

Lutra lutra compared with Mustela itatsi

Key Differences

• European otter is Vulnerable while Japanese Weasel is Near Threatened.

Taxonomic Classification

Rank	European otter	Japanese Weasel
Kingdom same	Animalia (животные)	Animalia (животные)
Phylum same	Chordata (хордовые)	Chordata (хордовые)
Class same	Mammalia (млекопитающие)	Mammalia (млекопитающие)
Order same	Carnivora (хищные)	Carnivora (хищные)
Family same	Mustelidae (Weasels & Otters)	Mustelidae (Weasels & Otters)
Genus	Lutra (Otters)	Mustela
Species	Lutra lutra	Mustela itatsi

Evolutionary Relationship

European otter and Japanese Weasel share a common ancestor at the Family level: Mustelidae. (Weasels & Otters)

Conservation Status

European otter

VU — Vulnerable

Trend: Stable →

Japanese Weasel

NT — Near Threatened

Physical Characteristics

Attribute	European otter	Japanese Weasel
Diet	Carnivore	—
Average Lifespan	10 years	—
Average Length	1.0 m	—
Average Weight	10.0 kg	—

Habitat & Geographic Range

European otter

Habitat

Typically found in diverse ecosystems where prey species are available.

Range

Found across Europe (6 countries). Currently classified as Vulnerable on the IUCN Red List, this species faces significant conservation challenges across its range.

Japanese Weasel

Habitat

Typically found in diverse terrestrial and aquatic ecosystems.

Range

Found in Japan. Listed as Near Threatened, this species requires ongoing monitoring to prevent population decline.

European otter

Sleek semi-aquatic mustelid found along clean rivers, streams, and coastlines across Europe and Asia. European otters can reach 1.3 meters in length and are highly skilled fish hunters, using sensitive whiskers to detect prey movements. Requiring unpolluted water with abundant fish, they are an indicator species for freshwater ecosystem health. Once nearly extinct in Western Europe from hunting and pollution, populations have recovered significantly following water quality improvements.