vs Common Seal

Biddulphia rhombus compared with Phoca vitulina

Key Differences

is Not Evaluated while Common Seal is Near Threatened.

Taxonomic Classification

Rank		Common Seal
Kingdom	Chromista (Chromista)	Animalia (Animals)
Phylum	Ochrophyta (Ochrophyta)	Chordata (Chordates)
Class	Bacillariophyceae (Bacillariophyceae)	Mammalia (Mammals)
Order	Biddulphiales (Biddulphiales)	Pinnipedia (Seals & Sea Lions)
Family	Biddulphiaceae	Phocidae (True Seals)
Genus	Biddulphia	Phoca (Harbor Seals)
Species	Biddulphia rhombus	Phoca vitulina

Conservation Status

NE — Not Evaluated

Common Seal

NT — Near Threatened

Population: ~500.0K

Trend: Stable →

Physical Characteristics

Attribute		Common Seal
Diet	—	Carnivore
Average Lifespan	—	30 years
Average Length	—	1.7 m
Average Weight	—	80.0 kg

Habitat & Geographic Range

Habitat

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

Range

Distributed across Denmark, Sweden, and Taiwan.

Common Seal

Habitat

Typically found in diverse ecosystems where prey species are available.

Range

Found across Europe (7 countries) and North America (United States). Listed as Near Threatened, this species requires ongoing monitoring to prevent population decline.

Biddulphia rhombus is a centric marine diatom with a distinctly bipolar, rhomboid to broadly lanceolate valve shape bearing prominent horn-like elevations. It inhabits coastal planktonic and benthic environments in temperate to warm seas worldwide. This photosynthetic diatom contributes to marine primary production in neritic coastal waters.

Common Seal

The most widely distributed pinniped, harbor seals inhabit temperate and subarctic coastal waters of both the North Atlantic and North Pacific. Adults reach up to 130 kg and spend roughly equal time at sea hunting fish, squid, and crustaceans and hauling out on beaches or rocks to rest. Their large, expressive eyes are adapted for underwater vision in low light. Harbor seals are a critical food source for orcas, sharks, and polar bears.