Polar bear vs St. James' shell

Ursus maritimus compared with Pecten maximus

Key Differences

Polar bear is Vulnerable while St. James' shell is Least Concern.

Taxonomic Classification

Rank	Polar bear	St. James' shell
Kingdom same	Animalia (Animals)	Animalia (Animals)
Phylum	Chordata (Chordates)	Mollusca (Mollusks)
Class	Mammalia (Mammals)	Bivalvia (Bivalvia)
Order	Carnivora (Carnivorans)	Pectinida (Pectinida)
Family	Ursidae (Bears)	Pectinidae
Genus	Ursus (Bears)	Pecten
Species	Ursus maritimus	Pecten maximus

Evolutionary Relationship

Polar bear and St. James' shell share a common ancestor at the Kingdom level: Animalia. (Animals)

View Kingdom: Animalia

Conservation Status

Polar bear

VU — Vulnerable

Population: ~26.0K

Trend: Decreasing ↓

St. James' shell

LC — Least Concern

Physical Characteristics

Attribute	Polar bear	St. James' shell
Diet	Carnivore	—
Average Lifespan	25 years	—
Average Length	2.4 m	—
Average Weight	450.0 kg	—

Habitat & Geographic Range

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.

St. James' shell

Habitat

Native to Asia and Europe and South America, inhabiting ecosystems characteristic of the region.

Range

Widely distributed across Asia (China), Europe (8 countries), and South America (Chile).

Polar bear

The largest land carnivore on Earth, polar bears can exceed 700 kg and are found across Arctic sea ice from Canada to Russia. Highly specialized marine mammals that rely on sea ice to hunt ringed and bearded seals. Excellent swimmers capable of covering vast distances in open water. Listed as Vulnerable, with populations under severe pressure from rapid Arctic sea ice loss due to climate change.

St. James' shell

St. James' shell (Pecten maximus) is classified as Least Concern (LC) on the IUCN Red List. Widespread and abundant across its range, with stable populations and no immediate conservation concerns.