Common Seal vs sei whale

Phoca vitulina compared with Balaenoptera borealis

Key Differences

• Common Seal is Near Threatened while sei whale is Endangered.

Taxonomic Classification

Rank	Common Seal	sei whale
Kingdom same	Animalia (Animals)	Animalia (Animals)
Phylum same	Chordata (Chordates)	Chordata (Chordates)
Class same	Mammalia (Mammals)	Mammalia (Mammals)
Order	Pinnipedia (Seals & Sea Lions)	Cetacea (Whales & Dolphins)
Family	Phocidae (True Seals)	Balaenopteridae (Rorquals)
Genus	Phoca (Harbor Seals)	Balaenoptera (Rorquals)
Species	Phoca vitulina	Balaenoptera borealis

Evolutionary Relationship

Common Seal and sei whale share a common ancestor at the Class level: Mammalia. (Mammals)

Conservation Status

Common Seal

NT — Near Threatened

Population: ~500.0K

Trend: Stable →

sei whale

EN — Endangered

Physical Characteristics

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

Habitat & Geographic Range

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.

sei whale

Habitat

Typically found in diverse terrestrial and aquatic ecosystems.

Range

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

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.

Shared Countries

Both species can be found in 4 countries:

🇩🇰 Denmark 🇳🇴 Norway 🇵🇹 Portugal 🇸🇪 Sweden