What's the difference?

Seals and sea lions belong to different families. True seals lack external ear flaps, have short front flippers, and move on land by wiggling their bodies. Sea lions have external ear flaps, large front flippers they use like arms, and walk on all four flippers. Seals are generally better divers while sea lions are more agile on land.

Seals are carnivores eating fish, squid, octopus, crustaceans, and sometimes other marine mammals. Diet varies by species and location. Most seals are opportunistic, consuming whatever prey is abundant. Leopard seals hunt penguins and seal pups. Crab eater seals filter krill through specialized teeth. Seals must eat 5 to 10 percent of body weight daily.

How deep can seals dive?

Diving depths vary dramatically by species. Elephant seals hold the record at over 7,000 feet deep. Weddell seals dive to 2,000 feet. Harbor seals typically reach 300 to 600 feet. Deep diving seals have adaptations including collapsible rib cages, high blood oxygen capacity, and extreme bradycardia that slows heart rate to 4 beats per minute.

Do seals live in groups?

Social behavior varies by species. Many seals form large colonies on beaches or ice during breeding and molting seasons. Elephant seals gather in colonies of thousands. Harbor seals are more solitary, maintaining individual space even when hauled out near each other. Seals benefit from group vigilance against predators and synchronized breeding seasons.

How long do seals live?

Seal lifespans vary by species. Small harbor seals live 20 to 30 years. Large elephant seals can reach 20 years for males and 22 years for females. Gray seals live 25 to 35 years. Factors affecting lifespan include predation, food availability, disease, and human impacts. Females generally outlive males in most species.

Can seals live in freshwater?

Most seals live in saltwater, but a few species inhabit freshwater permanently. Baikal seals live exclusively in Siberia's Lake Baikal. Caspian seals inhabit the Caspian Sea. Ringed seals occupy some freshwater lakes in Canada and Finland. These species evolved from marine ancestors that became landlocked as water levels changed thousands of years ago.

How do seals stay warm?

Seals maintain body temperature through thick blubber layers up to 4 inches thick. Blubber provides insulation and energy reserves. Their circulatory system includes countercurrent heat exchangers in flippers that minimize heat loss. Seals have low surface area to volume ratios. Small blood vessels in flippers constrict in cold water, reducing heat loss.

Seal Facts: Species, Diving Ability & Behavior

Marine mammals adapted for ocean life

Seals are marine mammals with 33 species worldwide. Learn about seal diving abilities, adaptations, social behaviors, and their crucial roles in ocean ecosystems.

Key Facts

Species

33 species

Smallest

Baikal seal (110 lbs)

Largest

Elephant seal (8,800 lbs)

Dive Depth

Up to 7,000 feet

Dive Duration

Up to 2 hours

Swimming Speed

20 to 25 mph

Lifespan

15 to 40 years

Diet

Carnivore

Whiskers

Highly sensitive

Vision

Adapted for underwater

Blubber Thickness

Up to 4 inches

Pups

Usually 1 per year

Quick Stats

Attribute	Value
Number of Species	33 species
Elephant Seal Weight	Up to 8,800 lbs (males)
Harbor Seal Weight	180 to 285 lbs
Maximum Dive Depth	7,000 feet (elephant seal)
Dive Duration	Up to 2 hours
Swimming Speed	20 to 25 mph
Gestation Period	9 to 11 months
Milk Fat Content	35 to 50 percent

About Seal Facts: Species, Diving Ability & Behavior

Seals are marine mammals belonging to the family Phocidae, commonly called true seals or earless seals. With 33 species distributed from polar ice to tropical waters, seals are superbly adapted for ocean life.

Physical Adaptations for Diving

Seals possess remarkable adaptations for deep, long duration dives. Their streamlined, torpedo shaped bodies minimize drag underwater. Thick blubber layers up to 4 inches provide insulation and energy reserves. Before diving, seals slow their heart rate from 100 beats per minute to as few as 4 beats per minute.

Senses and Hunting

Seals rely on multiple senses for hunting in dark, murky waters. Their most remarkable sensory adaptation is whiskers, called vibrissae. These highly sensitive organs detect water movements created by swimming fish from over 500 feet away. Seals can determine prey size, shape, and swimming speed through whisker vibrations.

Diet and Feeding Behavior

Most seals are opportunistic feeders consuming whatever prey is abundant. Elephant seals dive to ocean depths over 7,000 feet hunting deep water fish and squid. Harbor seals typically dive to 300 feet pursuing bottom dwelling fish. Seals must consume 5 to 10 percent of their body weight daily to maintain their metabolism and blubber reserves.

Social Behavior and Communication

Social structures vary among seal species. Many form large colonies on beaches or ice during breeding and molting seasons. Harbor seals are relatively solitary, gathering in groups but maintaining individual space. Mothers and pups recognize each other's unique vocalizations among thousands of individuals.

Reproduction and Pup Development

Females typically give birth to single pups once yearly after 9 to 11 month gestation periods that include delayed implantation. Mothers produce extremely rich milk containing 35 to 50 percent fat, the highest of any mammal. Hooded seal pups double their birth weight in just 4 days. First year mortality is high at 30 to 50 percent from starvation, predation, and storms.

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Did You Know?

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Elephant seals can dive over 7,000 feet deep and hold their breath for 2 hours

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Seal milk contains 35 to 50 percent fat, the richest of any mammal

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Seals' whiskers detect fish movements from over 500 feet away in complete darkness

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Hooded seal pups gain 15 pounds per day, doubling birth weight in just 4 days

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Weddell seals produce complex underwater songs that travel for miles

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Leopard seals are apex predators that hunt penguins and other seal species

Frequently Asked Questions

Seal breath holding abilities vary by species. Elephant seals can hold their breath for over 2 hours while diving to depths exceeding 7,000 feet. Weddell seals hold their breath for 90 minutes. Harbor seals typically dive for 3 to 7 minutes but can extend to 30 minutes when needed. These abilities result from high oxygen storage capacity and metabolic adaptations.