Common Seal vs Smooth Stonewort

Phoca vitulina compared with Nitella flexilis

Key Differences

Common Seal is Near Threatened while Smooth Stonewort is Least Concern.

Taxonomic Classification

Rank	Common Seal	Smooth Stonewort
Kingdom	Animalia (Animals)	Plantae (Plants)
Phylum	Chordata (Chordates)	Charophyta (Charophyta)
Class	Mammalia (Mammals)	Charophyceae (Charophyceae)
Order	Pinnipedia (Seals & Sea Lions)	Charales (Charales)
Family	Phocidae (True Seals)	Characeae
Genus	Phoca (Harbor Seals)	Nitella
Species	Phoca vitulina	Nitella flexilis

Conservation Status

Common Seal

NT — Near Threatened

Population: ~500.0K

Trend: Stable →

Smooth Stonewort

LC — Least Concern

Physical Characteristics

Attribute	Common Seal	Smooth Stonewort
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.

Smooth Stonewort

Habitat

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

Range

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

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.