While fish can spend their whole lives under the water’s surface whales have to rise to the surface to breathe This is because whales unlike fish are mammals A mammal is an animal that breathes air has a backbone and grows hair at some point during its life All female mammals can produce milk for their young Animals within this LIFE IN THE OCEAN Humpback whales are very acrobatic marine mammals They often leap out of the water and then arch backward as they fall back down 4
group are among the most intelligent of all living creatures Humans are a part of this group Mammals that live in the world’s oceans are called marine mammals Whales are marine mammals So are seals sea lions walruses manatees polar bears and sea otters Some marine mammals such as whales live their whole lives in the water Others such as polar bears spend part of their time on land Whales and sharks both live in oceans but whales are marine mammals and sharks are fish Compare and contrast the two Compare and Contrast Manatees spend their whole lives in the water These two are off the coast of Florida 5
Mammals are the only animals that make milk to nourish their young The female has special glands called mammary glands After childbirth the mother’s glands produce milk The mother feeds the young with this milk until the young are old enough to get WHAT MAKES A MAMMAL This baby manatee is drinking its mother’s milk Manatee mothers and calves communicate with sounds They make chirps squeaks and grunts Glands are body parts that make and release things like sweat milk and spit Vocabulary 6
food for themselves Marine mammal milk has a lot of fat in it This helps the babies grow quickly All mammals have hair at some stage of development Some marine mammals have more than others For example the thick fur coat of sea otters keeps them warm in the cold waters where they live On the other hand whales have very little hair Some whales have hair only before they are born A thick layer of fat called blubber keeps them warm instead Some marine mammals such as fur seals have both thick coats and blubber Sea otters have the thickest fur of any animal Their coats have a soft undercoat and longer guard hairs 7
