Warm-blooded animals that have adapted to live in the sea.
This category includes animals that live in the sea all the time, as well as ones that come up on land too.
Dolphins are a medium sized animal that lives in the water, mainly the sea but they are also found in lakes and rivers. They are not fish, as they need to come to the surface to breathe, the same as we do when we are swimming. Dolphins eat mostly fish. They are intelligent and can be taught tricks.
Manatees, also called sea cows, are mammals closely related to the dugong. They grow to around 3 meters long, and weigh around 4,000 pounds (1,700kg). They eat plants in fairly shallow water around the coast and in rivers.
The orca, or killer whale, is the largest member of the dolphin family. They are found in oceans all over the world. Orcas are hunters, and will eat fish, sharks, seals and even whales. They grow to around 6-8 metres long, and can live to be 80 years old, although most males only get to be 30 and females 50. A female orca will have one calf every 5 years.
Seals are a large animal that spends most of its time in the sea. Seals eat fish, and come up onto the beach to rest and have baby seals. The closest land relative to the seal is the bear, and their closest relatives in the water are walruses.
A walrus is a large animal that spends most of its time in the sea. They eat clams, sea snails and other animals from the bottom of the sea. They can live to about 50 years old, and a male walrus can grow to weigh between 1,600 and 1,900kg, and get 10-12 feet long. They are distantly related to the seal.
Whales are a large animal that lives in the sea. They are not fish, as they need to come to the surface to breathe, the same as we do when we are swimming. There are many different varieties of whale. Some eat fish, penguins and seals, but the majority of whales have a large mouth full of tiny bristles that they use to filter tiny sea animals out from the water to eat.
The whale is closely related to the dolphin.