Common Bithynia vs Polar bear

Bithynia tentaculata compared with Ursus maritimus

Key Differences

• Common Bithynia is Least Concern while Polar bear is Vulnerable.

Taxonomic Classification

Rank	Common Bithynia	Polar bear
Kingdom same	Animalia (动物界)	Animalia (动物界)
Phylum	Mollusca (软体动物门)	Chordata (脊索动物门)
Class	Gastropoda (腹足纲)	Mammalia (哺乳動物)
Order	Littorinimorpha (滨螺形目)	Carnivora (食肉目)
Family	Bithyniidae	Ursidae (Bears)
Genus	Bithynia	Ursus (Bears)
Species	Bithynia tentaculata	Ursus maritimus

Evolutionary Relationship

Common Bithynia and Polar bear share a common ancestor at the Kingdom level: Animalia. (动物界)

Conservation Status

Common Bithynia

LC — Least Concern

Polar bear

VU — Vulnerable

Population: ~26.0K

Trend: Decreasing ↓

Physical Characteristics

Attribute	Common Bithynia	Polar bear
Diet	—	Carnivore
Average Lifespan	—	25 years
Average Length	—	2.4 m
Average Weight	—	450.0 kg

Habitat & Geographic Range

Common Bithynia

Habitat

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

Range

Distributed across Belgium, Denmark, Norway, Sweden, and United States.

Polar bear

Habitat

Found across multiple habitat types including temperate broadleaf and mixed forests, temperate coniferous forests, and boreal forests and taiga, among 4 distinct biome types within the Palearctic biogeographic realm. Populations are also found in montane and highland environments at higher elevations.

Range

Found in Norway. Currently classified as Vulnerable on the IUCN Red List, this species faces significant conservation challenges across its range.

Common Bithynia

The common bithynia (<em>Bithynia tentaculata</em>) is a freshwater gastropod snail belonging to the family Bithyniidae. It is classified as Least Concern on the IUCN Red List and has been recorded across terrestrial and aquatic habitats in Belgium, Denmark, Norway, Sweden, and the United States. <em>Bithynia tentaculata</em> typically inhabits slow-moving or still freshwater environments such as lakes, ponds, canals, and rivers, often on muddy or sandy substrates where organic material is abundant. The species has a distinctive operculum that seals the shell opening, providing protection against desiccation and predators. It typically feeds by grazing on algae, detritus, and biofilms on submerged surfaces. The common bithynia serves as an intermediate host for several trematode parasites, making it ecologically significant in freshwater food webs and parasite life cycles. Biological traits of this species remain poorly documented in the scientific literature.

Polar bear

北极熊是地球上最大的陆地食肉动物，体重可超过700千克，分布于从加拿大到俄罗斯的北极海冰区。是高度特化的海洋哺乳动物，依赖海冰捕猎环斑海豹和髯海豹。是优秀的游泳者，能够横渡广阔的开阔水域。被列为易危种，因气候变化导致北极海冰迅速减少，种群正受到严重威胁。

Shared Countries

Both species can be found in 1 countries:

🇳🇴 Norway