Difference Between Seal and Sea Lion

Main Difference – Seal vs Sea Lion

Seals, sea lions, and walruses are commonly known as pinnipeds. The name ‘pinniped’ means the ‘fin-footed,’ which reflects their ability to live on land and in water. Pinnipeds are classified under three families, eared seals, true seals and walruses. Eared seals include both sea lions and fur seals due to the presence of small external ears, which make them different from true seals. In this article, we have used the term seals to refer to true seals. The main difference between seal and sea lion is that seals belong to family Phocidae whereas sea lions belong to family Otariidae. This article further explains the difference between seal and sea lion.

Similarities Between Seal and Sea Lion

Before looking at the difference between seal and sea lion, let us first look at some of their common features. Unlike other marine mammals, these creatures can stay in both marine and terrestrial environments for very long periods. Pinnipeds show great adaptations as marine mammals. Their sleek, streamlined bodies help them to dive efficiently under water with less effort. Their appendages are modified into fins and flippers enabling them to propel through water at greater speeds. The fur of most pinnipeds has disappeared to enhance the streamlining effect. Moreover, the presence of the large-sized compact body, blubber, and rapid metabolism rates help them to regulate body temperatures even in extremely cold waters. In addition, these mammals have evolved the ability to conserve oxygen while they stay in the water for prolonged periods. All pinnipeds reproduce and give birth on land. Their main diet is small fish. Though they are very efficient in marine habitats, they cannot move efficiently on land. Due to this reason, they are very vulnerable to land predators.

Seal – Facts, Characteristics, and Behaviour

There are two types of seals according to the classification of Pinnipeds; fur seals and true seals. Fur seals are actually eared seals, which belong to family Otariidae. In this article, we consider them as true seals, which belong to family Phocidae. True seals mainly differ from sea lions and fur seals due to the lack of external ears. In addition, seals use front flippers to move on land and hind flippers for swimming. Seals are often recognized by having spots, rings or patches on their bodies.

Sea Lion – Facts, Characteristics and Behaviour

Sea lions are classified under family Otariidae and are characterized mainly by the presence of small external ears. These marine mammals can walk on land using both front and hind flippers. Their front flippers are usually larger than those of seals. They gain the propulsive force for swimming mainly by forelimb movement, which looks like flying underwater. Their hind limbs are only used for steering while swimming. Unlike seals, sea lions do not have patches or spots on their body. Sea lion’s body is generally brown to tan in color.