Common Seal vs

Phoca vitulina compared with Cylindrotheca closterium

Key Differences

Common Seal is Near Threatened while is Not Evaluated.

Taxonomic Classification

Rank	Common Seal
Kingdom	Animalia (Animals)	Chromista (Chromista)
Phylum	Chordata (Chordates)	Ochrophyta (Ochrophyta)
Class	Mammalia (Mammals)	Bacillariophyceae (Bacillariophyceae)
Order	Pinnipedia (Seals & Sea Lions)	Bacillariales (Bacillariales)
Family	Phocidae (True Seals)	Bacillariaceae
Genus	Phoca (Harbor Seals)	Cylindrotheca
Species	Phoca vitulina	Cylindrotheca closterium

Conservation Status

Common Seal

NT — Near Threatened

Population: ~500.0K

Trend: Stable →

NE — Not Evaluated

Physical Characteristics

Attribute	Common Seal
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.

Habitat

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

Range

Distributed across Brazil, Norway, Oman, Sweden, and Taiwan.

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.

Cylindrotheca closterium is an elongated, needle-shaped marine and brackish water diatom common in coastal sediments, intertidal mudflats, and benthic biofilms worldwide. Its spindle-shaped silica frustule tapers to fine points at both ends. This species is an important primary producer in estuarine and shallow coastal ecosystems and can form dense mats on sediment surfaces.