Pinnipeds are large furry fin or flipper footed carnivorous semi-aquatic marine mammals. While pinnipeds live primarily in the ocean, they can come on land for long periods of time. Millions of years ago, pinnipeds were land-dwelling creatures; it is believed that they were bear or weasel-like animals that spent increasing amounts of time in the ocean and eventually adapted to the marine environment. Pinnipeds have advanced senses with sight and sense of smell adapted to both air and water and whiskers with an advanced tactile system. Pinniped have a layer of blubber, or fat, under their skin to help them retain heat and stay warm in the cold water habitats they typically inhabit in the Northern and Southern hemispheres.
The largest pinniped on record is the southern elephant seal measuring 21.3 ft (6.5 m) captured in 1913. The average male southern elephant seal can weigh between 4,900 to 8,800 lbs (2,200 to 4,000 kg) and are 14 ft to 19 ft (4.2 to 5.8 m) long. Bulls are typically 5 to 6 times heavier than females.
Pinnipeds are carnivorous and eat a wide variety of food depending on their species and habitat. They typically eat krill, crustaceans, mollusks, fish, and squid. Most pinnipeds are general feeders but some specialize, like the leopard seal that specializes in penguins. Ross seals and southern elephant seals generally only eat squid and crabeater seals feed mostly on krill.
Blubber, layers of fat under their skin, is important for pinnipeds because it helps them protect themselves from the cold. The layers of blubber also aides in streamlining their form which allows pinnipeds to effectively chase after their prey. Blubber is also important for newborn pups as they live off their blubber while they develop both their diving and feeding skills.