Marine Mammals

 Mammals have a 4 chambered heart.  Mammals are warm- blooded.  They have hair/fur.  Have mammary glands.  Give birth to live young.

Pinnepeds Ex: Seals, Walruses, Sea Lions. Marine mammals that have flippers and blubber Need to breed on land. Live in cold water, and have a thick layer of blubber to keep them warm. Mostly carnivores and feed on squid and fish. Streamlined bodies and are excellent swimmers.

Seals Seals have rear flippers. They move forward by pulling themselves along the ground. Seals do not have ear flaps. There are approximately 19 species of Seals.

Sea Lions Are also called Eared Seals, because they have external ear flaps. They can move their rear flippers forward to walk. They are graceful and agile swimmers.

Walruses Have large protruding tusks for digging up mollusks. They have stiff whiskers for feeling around on the ocean floor. They are the largest Pinneped, weighing up to 2700 lbs!

Sea Otters They are the smallest Marine Mammal, weighing lbs. They lack a layer of blubber, and make up for it by trapping air in their dense fur. They eat mostly shell fish and spend most of the day maintaining their fur.

Polar Bears They are semi aquatic, so inhabit both the land and the sea. They feed primarily on seals. They have recently been put on the endangered species list because of loss of habitat due to global warming.

Cetaceans These animals spend their entire lives in the water. They are streamlined, and look fish-like. They breathe air through lungs and have nostrils on the tops of their heads called a blowhole (some single, some double). This is the largest group of Marine Mammals, consisting of Whales, Dolphins, and Porpoises. There are more than 90 species divided into two groups: toothed Whales (which includes Dolphins and Porpoises), and toothless Whales which have a Baleen.

Baleen Whales Instead of teeth, Baleen Whales have rows of flexible, fibrous plates, that hang from the upper jaws (called a Baleen). These are used to filter out plankton and tiny organisms from the water. Baleen Whales are the largest animals to ever have lived on this planet. There are 13 species of Baleen Whales; the Blue Whale being the largest at up to 110 ft. long, and up to 200 tons.

Toothed Whales Teeth are adapted for a diet of squid, fish, and other prey and are used to catch and hold prey, not to chew it. There are 80 species of toothed Whales. The largest of the toothed Whales is the Sperm Whale, made famous by the novel “Moby Dick”.

Dolphins Highly intelligent creatures, that can be easily trained, are playful, and have been known to “escort” ships. It is common for dolphins to get caught in fishing nets meant for other species.

Porpoises Porpoises are divided in to six species. Shorter than the average dolphin, more shy, and they don’t tend to live as long. Have flattened, spade-shaped teeth.

Dall's Porpoise Harbour Porpoise

Narwhals Related to bottlenose dolphins, belugas, harbor porpoises, and orcas. Found in Arctic coastal waters and rivers. In males, a prominent tooth grows right through the upper lip into a sword like, spiral tusk up to 2.7 meters long. Some believe it is used to impress females or to battle rival suitors. They travel in groups and feed on fish, shrimp, squid, and other aquatic fare. Inuit people hunt the narwhal for their long tusks and their skin, an important source of vitamin C

Belugas Belugas are also called white whales. Smallish (4 to 6.1 meters). They have rounded foreheads and no dorsal fin. Common in the Arctic Ocean's coastal waters Feed on fish, crustaceans, and worms. Related to the narwhal.

Communication One way Cetaceans communicate is through Echolocation (nature’s version of sonar). They release tiny bubbles through their blowholes and make clicking sounds to communicate with each other, determine distances, and warn others about danger. The Melon (fatty structure on the top of their heads) focuses and directs these sound waves.

Breaching When Whales leap in the air and loudly crash on the surface of the water. This can be a warning signal, a way to get rid of external parasites, a fun activity, or a way of scanning the surface.