Big Finner vs European otter

Balaenoptera physalus compared with Lutra lutra

Key Differences

• Big Finner is Endangered while European otter is Vulnerable.

Taxonomic Classification

Rank	Big Finner	European otter
Kingdom same	Animalia (Animals)	Animalia (Animals)
Phylum same	Chordata (Chordates)	Chordata (Chordates)
Class same	Mammalia (Mammals)	Mammalia (Mammals)
Order	Cetacea (Whales & Dolphins)	Carnivora (Carnivorans)
Family	Balaenopteridae (Rorquals)	Mustelidae (Weasels & Otters)
Genus	Balaenoptera (Rorquals)	Lutra (Otters)
Species	Balaenoptera physalus	Lutra lutra

Evolutionary Relationship

Big Finner and European otter share a common ancestor at the Class level: Mammalia. (Mammals)

Conservation Status

Big Finner

EN — Endangered

European otter

VU — Vulnerable

Trend: Stable →

Physical Characteristics

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

Habitat & Geographic Range

Big Finner

Habitat

Found across multiple habitat types including tropical and subtropical dry broadleaf forests, flooded grasslands and savannas, and montane grasslands and shrublands, among 4 distinct biome types within the Neotropic biogeographic realm.

Range

Widely distributed across Asia (Taiwan), Europe (5 countries), and South America (Colombia, Ecuador, Venezuela). Currently classified as Endangered on the IUCN Red List, this species faces significant conservation challenges across its 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.

Big Finner

Big Finner (Balaenoptera physalus) is classified as Endangered (EN) on the IUCN Red List. At high risk of extinction in the wild, with significant population decline and ongoing threats to survival.

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.

Shared Countries

Both species can be found in 4 countries:

🇧🇪 Belgium 🇩🇰 Denmark 🇳🇴 Norway 🇸🇪 Sweden