Marine Mammals What is a Mammal Mammals have

Marine Mammals

What is a Mammal? • Mammals have a 4 chambered heart. • Mammals are warmblooded. • They have hair/fur. • Have mammary glands. • Give birth to live young.

Pinnepeds • Pinnepeds are marine mammals that have flippers and blubber, that need to breed on land. • Seals, Walruses, and Sea Lions all belong to this Order. • Pinnepeds live in cold water, they have a thick layer of blubber to keep them warm. • They are mostly carnivores and feed on squid and fish. • They have streamlined bodies and are excellent swimmers. • Seals are the largest group of pinnepeds.

Seals • Seals have rear flippers. • They move forward by pulling themselves along the ground. • Seals do not have ear flaps. • They are hunted for their fur and are protected by the Marine Mammal Protection Act of 1972. • There 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. • These are the “guys” that you see at Marine World or an Aquarium doing neat tricks and they also work for the US Navy! • At one time they were hunted for their fur, but are now protected by the MMPA of 1972.

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

Sea Otters • Are members of the Order Carnivora. • They are the smallest Marine Mammal, weighing 60 -80 lbs. • They lack a layer of blubber, and make up for it by trapping air in their dense fur. • They were slaughtered to the brink of extinction for their beautiful fur, but became protected by an international agreement in 1911. • They are playful, and intelligent. • They eat mostly shell fish and spend most of the day maintaining their fur.

Polar Bears • Is the second member of the order Carnivora that is a Marine Mammal. • They are semi aquatic, and inhabit both the land 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 • This is the largest group of Marine Mammals, consisting of Whales , Dolphins, and Porpoises. • These, of all the Marine Mammals, have made the most complete transition to aquatic life. • These animals spend their entire lives in the water. • They are streamlined, and look remarkably fish-like. • They breathe air through lungs and have nostrils on the tops of their heads called a blowhole (some single, some double).

• There are more than 90 species of Cetaceans. • They are divided into two groups: toothed Whales (which includes Dolphins and Porpoises), and toothless Whales which have a Baleen. • 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.

• The remaining 80 species of Cetaceans are toothed Whales. • Their teeth are adapted for a diet of squid, fish, and other prey. • Teeth are used to catch and hold prey, not to chew it. • The largest of the toothed Whales is the Sperm Whale, made famous by the novel “Moby Dick”. • Killer Whales, or Orcas, are beautiful black and white Whales that are predators, eating seal, penguins, sea otters, and fish. • They are more common in cold water, but are found round the world.

• Dolphins are highly intelligent creatures, and can be easily trained. . • They are very playful, and have been known to “escort” ships for miles at a time. • Porpoises are really blunt nosed smaller Whales. • Dolphins, Porpoises, and Whales travel in groups called Pods. • They are protected by the MMPA of 1972, but are still hunted. • The Japanese, and Norwegian fishing Industries have been illegally whaling under false pretenses ( scientific whaling). • It is common for Cetaceans to get caught in fishing nets meant for other species.

Communication • One way Cetaceans communicate is through Echolocation. • They release tiny bubbles through their blowholes and make clicking sounds to communicate with each other and determine distances, and warn others about danger. • This is natures version of Sonar. • The Melon (fatty structure on the top of their heads) focuses and directs these sound waves. • Cetaceans produce a rich variety of sounds tha are associated with different moods, sexual signaling, feeding, alarms……

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

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