Pinniped

Pinnipeds, commonly known as seals, are a group of carnivorous, fin-footed, semiaquatic marine mammals. They include the walrus, sea lions, fur seals, and true seals. These animals have streamlined bodies and limbs changed into flippers. This helps them move easily in water. Though not as fast as dolphins, they are good at swimming and diving.

Seals vary in size, from the small Baikal seal to the large southern elephant seal. They live mainly in cold waters and spend most of their time in the ocean. They come ashore to mate, give birth, or escape predators. Their food is mostly fish and marine invertebrates, though some eat larger animals.

Traditionally, indigenous peoples of the Arctic have used the meat, blubber, and skin of seals. Seals appear in many cultures and are sometimes kept in captivity. Once heavily hunted, seals are now protected by international law. However, some species, like the Mediterranean monk seal and the Hawaiian monk seal, are endangered due to threats such as accidental trapping, marine pollution, climate change, and conflicts with local people.

Etymology

The name "pinniped" comes from Latin words pinna meaning 'fin' and pes, pedis meaning 'foot'. The word "seal" comes from an old English word called seolh, which itself comes from an even older language called Proto-Germanic.

Taxonomy

Further information: List of pinnipeds

Pinnipeds, often called seals, are marine mammals. They include walruses, sea lions, fur seals, and true seals. They belong to the order Carnivora and are part of the suborder Caniformia, which includes animals related to dogs.

There are three main families of pinnipeds: Odobenidae (walruses), Otariidae (eared seals, including sea lions and fur seals), and Phocidae (true or earless seals). Today, there are 34 different species of pinnipeds.

Scientists have studied these animals for many years. They were first recognized as a special group in 1811. Recent studies show that all pinnipeds likely came from one common ancestor. These animals have special features that help them swim and move on land, such as flippers and strong bodies. Some, like the walrus, have large tusks, while others, like sea lions, can "walk" on land using their flippers.

Anatomy and physiology

Pinnipeds, known as seals, have streamlined bodies with flippers instead of legs. They have small ears and flexible necks. Their teeth are pointed to grip slippery fish. Walruses are special because they have long tusks.

Seals come in different sizes, from the small Baikal seal to the large southern elephant seal. Some males are much bigger than females. Most seals have fur, but walruses have sparse hair. Their fur helps keep them warm, and they also have thick blubber underneath their skin.

Seals swim using their flippers. Some move their front flippers like wings, while others use their back flippers to push through the water. On land, they move by flopping or walking on their flippers. Their eyes are good for seeing both underwater and in air, and they can sense vibrations in the water with their whiskers to find food.

Distribution and habitat

Living pinnipeds live in cold ocean waters. You can find them in the North Atlantic, the North Pacific, and the Southern Ocean. They do not live in warm Indomalayan waters. Some seals, like monk seals and certain sea lions, live in tropical and subtropical areas. They live where currents bring cooler water.

Pinnipeds live in many kinds of water. They live in coastal areas, the open ocean, deep waters near islands, brackish waters, and even freshwater lakes and rivers. The Baikal seal is the only one that lives only in freshwater. On land, seals use many surfaces. They use rocky shores, sandy beaches, sandbanks, and sea caves. In polar regions, they often rest on fast ice and drift ice.

Behavior and life history

Pinnipeds live both in water and on land. They spend most of their time in the water but come onto land to have babies, shed their fur, rest, or escape danger. Some species travel very far, especially when the environment changes. For example, elephant seals spend most of the year at sea and travel long distances between where they have babies and where they shed their fur.

Pinnipeds dive to find food or to escape danger. The Weddell seal can dive up to 600 meters and stay underwater for over 70 minutes, while northern elephant seals can dive over 1,500 meters and stay under water for more than an hour. They mostly eat fish and squid, but they also eat small sea animals, shellfish, zooplankton, and sometimes warm-blooded animals like sea birds. Some hunt alone, while others work together in groups. Pinnipeds are eaten by orcas, large sharks, and polar bears, among others. They often stay in groups to stay safe.

Their mating systems are different, with some species having one male with many females and others having one male and one female. Males often protect areas or groups of females. After birth, mothers care for their babies. Some mothers do not eat while caring for their babies, while others go out to find food and leave the babies behind. Baby pinnipeds usually start swimming on their own shortly after they are born. Pinnipeds make sounds to talk to each other and can even understand simple commands and recognize each other by voice.

Human relations

In culture

Further information: List of fictional pinnipeds

Many cultures have included seals in their stories and beliefs for thousands of years. In old tales, sea gods and goddesses often had links to seals. In some cold places, people believed in magical seals that could change from seal to human. Today, many people see seals as friendly, playful, and fun to watch.

In captivity

Seals and other seal-like animals are kept in special places around the world because people enjoy watching them. They have been kept since very old times, and they can learn to do tricks. Some places have big pools where the animals can swim, and others have smaller spaces. The most common animals in these places are California sea lions because they are easy to train. Some groups think it is not right to keep these animals in small spaces, as they need large ocean areas to live in the wild.

Hunting

Main article: Seal hunting

People have hunted seals for a very long time, using simple tools and later more advanced weapons. Seals are hunted for their meat, skin, and sometimes their tusks. There are differences between hunting by local communities, who need seals for food, and large-scale commercial hunting. Some seal groups have grown after hunting was limited, while others are still at risk. Some countries still allow controlled hunting of seals, but this remains a topic of discussion around the world.

Conservation issues

Pinnipeds, or seals, face several threats to their survival. Many get caught accidentally in fishing nets and can be harmed. Pollution builds up in their bodies and can affect their health.

Climate change poses a risk, especially for seals that live in polar areas. Less sea ice affects their breeding and survival. Some seal populations have grown and sometimes conflict with people, such as using docks for resting or competing with fisheries. Laws like the Marine Mammal Protection Act of 1972 help protect seals, but managing these conflicts remains a challenge.