Seals are fascinating creatures that inhabit oceans, rivers, and even lakes worldwide. From the sleek and majestic southern elephant seal to the curious harp seal, these marine mammals come in various sizes, shapes, and colors.
Each species has a unique diet, habitat, and behaviors that make them exciting and unique.
This article will explore 20 of the most common types of seals found worldwide and discuss their habitats, diets, and some interesting facts about them. Let’s dive in!
Table of Contents
What Are Seals?
True seals, also known as earless seals, are a group of aquatic mammals that belong to the family phocidae. They have a streamlined body, short front flippers, and no visible ear flaps.
Earless seals are pinnipeds and are found in cold and temperate waters around the world. These seals are adapted to living in the water, spending most of their time diving and hunting for food.
Otariidae is the family name for fur seals. These “eared” seals are distinguished by their long front flippers, external ear flaps, and the capacity to use their rear flippers to travel on land.
They are known for their thick, silky fur coats and may be found in both cold and warm waters.
Compared to other pinnipeds, true seals are more adapted to life in the water and have a less agile body on land.
Both pinnipeds are carnivorous, feeding on fish, squid, and other marine animals.
Scientific Name: Pagophilus groenlandicus
Other Names: Common Seal
Size: 280.6 lbs. (Adult)
Distribution: Northernmost Atlantic Ocean and Arctic Ocean
The harbor seal, often called the common seal, is a native of the coastal waters of the northern hemisphere.
Their V-shaped nostrils are distinctive, and they come in a variety of colors, usually silver, tan, brown, and gray. A typical adult can reach a length of 6.1 feet and weigh 250–370 pounds.
In the wild, harbor seals primarily feed on fish, mollusks, squid, crustaceans, and shellfish. Depending on the food availability, they may hunt near the shore or farther out in the ocean.
They’re often targeted by orcas, sea lions, sharks, and land predators, such as coyotes and foxes.
Fossil remains indicate these marine mammals have been around for 12 to 15 million years. Harbor seals have an average lifespan of 20-30 years, making them one of the longest-living pinnipeds. Perhaps most intriguing is their ability to stay submerged for more than 25 minutes and dive as deep as 1,600 feet.
Scientific Name: Halichoerus grypus
Other Names: Horseheads
Size: 680 lbs. (Adult Male)
Distribution: North Atlantic Ocean
With lengths up to 7.5 feet and weights up to 680 lbs, gray seals are larger than harbor seals. Their evenly spaced nostrils, straight head profile, and few or no markings on their silver-dark/gray coat make them easy to identify.
They reside in the North Atlantic Ocean on islands, ice shelves, and rocky coastlines.
These opportunistic feeders mainly consume fish like cod, eels, pollock, flatfish, and whiting.
They usually live up to 25-35 years and can spend more than two days out of water hunting for food.
Scientific Name: Erignathus barbatus
Other Names: Square flipper seal
Size: 617.3 lbs. (Adult)
Distribution: Subarctic and Arctic
Bearded seals can grow up to 8.9 feet in length and weigh an impressive 441-948 lbs. They’re easily recognizable by their long, whisker-like mustaches, short snout, and square front flippers.
Due to their dislike for deep waters, these seals mainly inhabit shallow, ice-covered waters. They primarily consume invertebrates like squid, crustaceans, clams, and shrimps but may occasionally target small fish. Bearded seals face threats from orcas, polar bears, and artificial pollution.
On England’s east coast, the kind was first noted in 1892. Since then, they have been crucial for studies and research into the oceans.
They normally have a lifespan of 25 to 30 years and are quite loud, frequently exchanging varied sounds and clicks.
Mediterranean Monk Seal
Scientific Name: Monachus monachus
Other Names: None
Size: 710 lbs. (Male, Adult), 660 lbs. (Female, Adult)
Distribution: Eastern Mediterranean and the Northeast Atlantic
The Mediterranean monk seal is one of the world’s most endangered seal species, with only 700 remaining. While they initially inhabited open beaches, increased human activity has forced them to seek refuge in sea caves.
An adult has a short gray and tufty coat and weighs between 530 and 880 lbs., with a maximum length of 7.9 feet.
As opportunistic predators, their diet consists of cephalopods, bony fish, and other crustaceans. They give birth in groups and have a lifespan of about 20-25 years.
The first description dates back to 1777 near the island of Cres, Croatia. Interestingly, they communicate by making high-pitched noises, especially when in danger.
Scientific Name: Hydrurga leptonyx
Other Names: Sea leopard
Size: 771.6 lbs. (Adult)
Leopard seals get their name from their coat’s distinctive spots resembling leopard markings. These powerful predators can measure up to 11.5 feet long and weigh over 1,300 lbs.
A leopard seal typically hunts penguins, krill, squid, and other seal pups, relying heavily on their agility and stealth to ambush their prey. Their natural enemy is the orca.
First documented in 1820 by French zoologist Henri Duvernoy, these marine mammals live for 26 years and prefer isolation.
A male leopard seal vocalizes when searching for a mate during breeding, whereas females do the same to attract a pup’s attention.
Northern Elephant Seal
Scientific Name: Mirounga angustirostris
Other Names: None
Size: 3,300–5,100 lbs. (Male), 880 to 1,980 lbs. (Female)
Distribution: West Coast of North America
The Northern elephant seal is one of the world’s largest pinniped species, with males reaching 16 feet in length and weighing up to 5,100 pounds. These seals have a large, barrel-shaped body, a long nose, and a prominent bulge at the neck.
Their diet consists mostly of squid, fish, and crustaceans, but they’ll eat anything they can find in the ocean, including sharks.
The northern elephant seal is vulnerable to predators such as great white sharks and orcas. A female has a lifespan of up to 19 years, with males reaching 13 years.
After being thought extinct, these elephant seals were rediscovered by a Smithsonian expedition in 1892 on Guadalupe Island. Its population has since been closely monitored.
Interestingly, they were nearly hunted to extinction in the 19th century for their blubber and fur. Conservation efforts have helped them return to a healthy population.
Scientific Name: Phoca largha
Other Names: Larga seal or largha seal
Size: 240 lbs. (Adult)
Distribution: North Pacific Ocean
The spotted seal is characterized by its gray to silver and white fur, with irregular dark spots covering its back and sides. They also have a narrow snout and round head and can grow 6.89 feet in length and 240 lbs.
Pups mainly feed on small crustaceans and krill, whereas adults hunt for small fish such as cod, capelin, and herring.
They love shallow waters less than 600 feet deep and can often be seen resting on sea ice.
Typical predators are orcas, sleeper sharks, polar bears, wolves, ravens, and humans. They have a maximum of 35 years of life, with very few reaching that age.
Scientific Name: Pusa caspica
Other Names: Phoca caspica
Size: 190 lbs. (Adult)
Distribution: Northern Caspian
The Caspian seal is the smallest seal species in the world, with adults reaching an average length of 4.25 feet and a weight of 190 lbs.
An adult has blackish-gray fur, with a distinctive white patch on the back and a berry for males.
They are piscivorous and hunt mainly in shallow waters for fish like the Caspian roach, gobies, anchovy sprat, and zander. Caspian seals can dive to depths of up to 164 feet.
This species is at risk from humans and predation by wolves and sea eagles. The International Union for Conservation of Nature (IUCN) named Caspian seals as endangered in 2008.
Hawaiian Monk Seal
Scientific Name: Monachus schauinslandi
Other Names: Ilio-holo-i-ka-uaua
Size: 485 lbs. (Adult)
Distribution: Hawaiian Islands
The Hawaiian monk seal is an endangered pinniped with a declining population of 1,400 individuals. It’s one of the only two remaining species in the family monachinae, the other being the Mediterranean monk seal.
It has a slender body, gray fur, and a white belly.
Hawaiian monk seals are generalist eaters and can be found in shallow water and near coral reefs, eating various fish, crustaceans, squids, eels, and octopuses. Some of its predators include Galapagos, tiger, and great white sharks.
A typical Hawaiian monk seal’s lifespan is 25-30 years. Females nurse their pups for only a month before leaving them on their own.
Scientific Name: Pusa sibirica
Other Names: None
Size: 196.2 lbs. (Adult)
Distribution: Lake Baikal, Siberia
The Baikal seal is the world’s only freshwater pinniped species. It’s also one of the smallest true seals, measuring 4.7 feet in length and weighing between 139 to 154 lbs.
You can recognize them by their consistent gray-brown fur on the upper body and yellowish undertone on their belly.
Unlike other seals, this species feeds primarily on golomyanka, an oilfish found only in Lake Baikal.
However, they may occasionally feed on Kessler’s sculpins and invertebrates like mollusks. Remarkably, they can live for up to 50 years, making them one of the longest-living pinnipeds.
Baikal is one of the oldest seal species, with fossils dating back 9,000 years. Their only known predator is the brown bear, with few instances being reported.
Unfortunately, this seal is threatened by habitat loss and human activity.
Scientific Name: Histriophoca fasciata
Other Names: Phoca fasciata
Size: 209 lbs. (Adult)
Distribution: North Pacific Ocean’s Subarctic and Arctic regions
Ribbon seals are medium-sized pinnipeds. They get their name from the two white cliques and wide white stripes on their dark brown coats.
The species weighs about 209 lbs. and live in open water, feeding on pelagic creatures like eelpouts, cephalopods, and Arctic cod.
The average lifespan of the ribbon seal is around 20 years, with a few reaching up to 30. They are solitary and very agile in the water. This pinniped has been observed to dive up to 656 feet deep and can stay submerged for around 30 minutes.
Predators include orcas, polar bears, and walruses. It has become a species of special concern in the United States.
Southern Elephant Seal
Scientific Name: Mirounga leonina
Other Names: None
Size: 3,300 to 8,200 lbs. (Males), 770 to 1,980 lbs. (Females)
Distribution: South Atlantic, South Indian Ocean, and Subantarctic Islands
The southern elephant seal is one of the largest seal species, with males weighing up to 8,200 lbs and measuring 19 feet in length.
They’re related to the northern elephant seal and can be found in the South Atlantic, South Indian Ocean, and Subantarctic Islands.
These pinnipeds are easily recognized by their massive proportions and large inflatable proboscis or snout. Due to their diving abilities, which can reach depths of 7,835 feet, southern elephant seals can forage for food more than most seals. Their diet includes fish, squid, and crustaceans.
Despite their size, predators such as orcas, leopard seals, and orcas prey on southern elephant seals, particularly the pups.
These marine mammals make deep rumbling roars during the breeding season, which can travel long distances.
Scientific Name: Leptonychotes weddellii
Other Names: None
Size: 880–1,320 lbs. (Adults)
The Weddell seal, named after British sailor James Weddell in the 1820s, is one of the most prevalent seal species in Antarctica. They’re relatively large, measuring 11.6 feet long and weighing about 1,320 lbs.
Aside from their bulky body, you can distinguish an adult by its short, broad snouts, small head, and dark gray fur with lighter gray patches.
Weddell seals are apex predators that dive as deep as 600 meters into ice holes in search of crustaceans, prawns, and cephalopods. And thanks to their ability to swim underwater for extended periods, they can evade predators like orcas and leopard seals. They have a lifespan of 25 years in the wild.
Intriguingly, Weddell seals communicate through different mediums. For instance, when in water, they can make distinct sounds like whistles and grunts to summon another from across the ice.
Scientific Name: Cystophora cristata
Other Names: Bladdernose seal
Size: 660–900 lbs. (Male), 320–661 lbs. (Female)
Distribution: North Atlantic and Arctic Oceans
The hooded seal is a rare pinniped found primarily in the North Atlantic and Arctic Oceans.
They have a distinctive appearance, with a big inflatable bladder on their head that they can blow up to appear more prominent when threatened or during mating. Their bodies typically feature silver-gray fur with varying sizes of dark patches.
Adult males are large, reaching up to 8.5 feet in length and weighing about 776 lbs., while the females are slightly smaller.
First documented in the 18th Century, these seals have the shortest lactation period of any mammal, lasting just four days.
The female milk is high in fat content, providing necessary nutrition to the pups for their rapid growth.
Scientific Name: Ommatophoca rossii
Other Names: None
Size: 284–476 lbs. (Male Adult)
Distribution: Antarctic and Sub-Antarctic
The Ross seal is one of the lesser-known Antarctic pinnipeds. They inhibit many environments, including ice floes, shallow coastal waters, and open ocean seas.
A Ross seal has enormous eyes, a small mouth, a dark to light brown dorsal coat, and dark and silvery-white undersides.
The average length of an adult is 6.9 ft, and they can weigh up to 476 lbs. These seals predominantly feed on fish, squid, and krill. Their predators include leopard seals and orcas.
Like the Weddell seal, they’re named after their founder, in this case, Sir James Clark Ross, commander of an Antarctic expedition in 1841.
Ross seals are capable of deep dives, reaching depths of up to 2,598 feet and staying underwater for up to 30 minutes.
Scientific Name: Pusa hispida
Other Names: None
Size: 309 lbs. (Adult)
Distribution: Arctic and sub-Arctic regions
Found in Sub-Arctic and Arctic regions, the ringed seal is relatively small. They reach up to 5.75 feet in length and weigh 309 lbs.
You can identify them by their dark coat with silver-colored circles along their sides, hence their name.
These seals feast on a variety of small fish (herring, cod, shrimp, and mysids) and invertebrates. They can dive up to 150 feet and hold their breath for more than 20 minutes to catch their prey.
Ringed seals are an essential food source for polar bears, Greenland sharks, and orcas.
A ringed seal can live for up to 30 years. Pups grow up to twice their size in just two months, making them one of the fastest-growing mammals.
Scientific Name: Lobodon carcinophagus
Other Names: Krill-eater seal
Size: 440 lbs. (Male)
Distribution: Antarctic Coast
The crabeater seal is primarily found along the Antarctic coast. Females are typically larger and heavier than males, reaching 7.8 feet in length and weighing up to 460 lbs.
However, this depends on the season, whether the seal is lactation or mating.
Contrary to popular belief, this seal feeds on Antarctic krill rather than crabs. They may also target cephalopods, cod, and grenadiers.
Crabeater seals have long, slender bodies with pointed snouts and are mostly covered in silver or brown fur with darker patches around the flippers.
Leopard seals are the main predator, particularly for young pups. One fun fact about crabeater seals is their snake-like wriggling when they walk, reaching speeds of up to 25 km per hour.
Antarctic Fur Seal
Scientific Name: Arctocephalus gazella
Other Names: Kerguelen fur seal
Size: 293 lbs. (Males), 74.9 lbs. (Females)
Distribution: Subantarctic Islands
The Antarctic fur seal species is highly adaptable with a population of over 4 million individuals. They’re usually dark brown, with females and pups being lighter. You may also recognize them by their pointed muzzle and long neck.
Adult males can reach up to six feet long and weigh up to 293 lbs, while females are typically smaller at 4.6 feet long and 74.9 lbs.
They spend most of their time in the water, foraging for fish, squid, krill, and sometimes birds. These seals have a maximum lifespan of 25 years, with males living for about 15 years and females for 20.
While they’re preyed upon by orcas and leopard seals, Antarctic fur seals are aggressive when on land and can be very protective of their pups. They can dive to depths of up to 590 feet and stay underwater for about 10 minutes.
Northern Fur Seal
Scientific Name: Callorhinus ursinus
Other Names: Sea bears
Size: 270 lbs. (Males), 320 lb (Females)
Distribution: Sea of Okhotsk, North Pacific Ocean, and Bering Sea
Northern fur seals predominantly inhabit rocky islands or open beaches, especially during breeding and resting. Females have a longer lifespan of 27 years, whereas males only live up to 18 years.
These seals are distinguished by their dense fur, small head, short snout, and stocky bodies. Males can weigh up to 600 lbs, whereas females average 130 lbs.
Being generalist predators, these mammals feed on various small fish and squid.
A northern fur seal is usually solitary, especially during winter. Females can recognize their young ones by making vocalizations.
Brown Fur Seal
Scientific Name: Arctocephalus pusillus
Other Names: South African fur seal, Cape fur seal, and Australian fur sea
Size: 440–660 lbs. (Male), 420–620 lbs. (Female)
Distribution: Southern Atlantic and Indian Oceans coastlines
The Brown fur seal, also known as the Cape fur seal, is one of the largest species of fur seals. Adult males reach up to 7.5 feet in length and weigh up to 660 lbs. The average lifespan is 15-20 years.
This species has a large, dog-like head and long front flippers, which they use to move around on land.
You can find them in groups on rocky shores, islands, and beaches, where they breed and feed.
Their diet consists mainly of fish and squid but will eat mollusks, crustaceans, and other marine animals. Brown fur seals are highly vocal and communicate using loud barks, grunts, and honks.
Frequently Asked Questions
You’ve learned about numerous types of seals, but you might still have questions about them.
What’s the difference between a seal and a sea lion?
Like the eared fur seals, sea lions have visible ear flaps and walk on the land using their large flippers. On the other hand, “true” or earless seals lack ear flaps and instead slide on their bellies. They also have small flippers and bodies, which help them move faster in water than sea lions. Another key difference is that seals are less noisy than sea lions as they can’t bark.
Why are seals called the dogs of the sea?
Seals are known as the “dogs of the sea” as they share many traits with canines. They are social animals that can bark, form strong bonds with their pups, and even display loyalty to their partners. Both earless seals and fur seals often play in the water like puppies or lounge on land like dogs.
How do seals use their whiskers?
Seals use their whiskers for navigation and locating prey in murky waters. They sense vibrations through the hairs, giving them vital information about their surroundings. The whiskers are shaped specifically to detect changes in water pressure so seals can navigate even when they can’t see.