blue whale vs common door snail

Balaenoptera musculus compared with Clausilia bidentata

Key Differences

• blue whale is Vulnerable while common door snail is Least Concern.

Taxonomic Classification

Rank	blue whale	common door snail
Kingdom same	Animalia (Animals)	Animalia (Animals)
Phylum	Chordata (Chordates)	Mollusca (Mollusks)
Class	Mammalia (Mammals)	Gastropoda (Gastropoda)
Order	Cetacea (Whales & Dolphins)	Stylommatophora (Stylommatophora)
Family	Balaenopteridae (Rorquals)	Clausiliidae
Genus	Balaenoptera (Rorquals)	Clausilia
Species	Balaenoptera musculus	Clausilia bidentata

Evolutionary Relationship

blue whale and common door snail share a common ancestor at the Kingdom level: Animalia. (Animals)

Conservation Status

blue whale

VU — Vulnerable

Population: ~15.0K

Trend: Increasing ↑

common door snail

LC — Least Concern

Physical Characteristics

Attribute	blue whale	common door snail
Diet	Carnivore	—
Average Lifespan	90 years	—
Average Length	30.0 m	—
Average Weight	150.0 t	—

Habitat & Geographic Range

blue whale

Habitat

Found across multiple habitat types including tropical and subtropical moist broadleaf forests, tropical and subtropical dry broadleaf forests, and tropical and subtropical grasslands and savannas, among 11 distinct biome types. Populations are also found in montane and highland environments at higher elevations.

Range

Widely distributed across Asia (Taiwan), Europe (4 countries), and South America (Colombia, Ecuador). Currently classified as Vulnerable on the IUCN Red List, this species faces significant conservation challenges across its range.

common door snail

Habitat

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

Range

Distributed across Belgium, Denmark, Norway, and Sweden.

blue whale

The largest animal ever known to have lived on Earth, blue whales can reach 33 meters and 200 tonnes — their hearts alone weigh as much as a small car. Found in all oceans, they migrate between polar feeding grounds and tropical breeding areas. Filter feeders consuming up to 4 tonnes of krill daily. Endangered, with global populations estimated at 10,000–25,000 after near-extinction from 20th-century whaling.

common door snail

<em>Clausilia bidentata</em>, the common door snail, is a terrestrial gastropod mollusk in the family Clausiliidae. This species is distributed across Belgium, Denmark, Norway, and Sweden, where it typically inhabits moist terrestrial environments including deciduous woodlands, rocky slopes, hedgerows, and the margins of freshwater habitats. The common door snail is recognized by its elongated, sinistral (left-handed) shell, which is a distinctive trait of the family Clausiliidae. The shell is typically brown to gray and reaches approximately 12–15 millimeters in length. <em>Clausilia bidentata</em> generally feeds on algae, lichens, fungi, and decaying plant material by rasping food with a radula. It often shelters under bark, stones, and leaf litter during dry or cold conditions. Like many clausiliids, it possesses a complex internal shell structure called a clausilium that closes the shell aperture to reduce desiccation. The species is assessed as Least Concern, reflecting stable populations across its European range. Detailed biological traits beyond those noted here are not extensively documented in the current scientific literature.

Shared Countries

Both species can be found in 3 countries:

🇩🇰 Denmark 🇳🇴 Norway 🇸🇪 Sweden