2. History According to fossil records, mammals made the transition from only land dwelling, to some water dwelling, about fifty million years ago. One of the most successful is the whale

3. Cetaceans Whales and Dolphins belong to the order Cetaceans The largest is the blue Whale at 30 meters long and weighing 150,000 kilograms it is the biggest animal to ever live on Earth The smallest are dolphins and porpoises they are extremely intelligent and highly social animals Whales are classified into two main groups Baleen and Toothed whales. Baleen are filter feeders, they eat zooplankton and small fish. They include the Blue, Finback, Humpback, Right, Minke, Sei, and Gray Whales. There are three different types of feeding for Baleen whales, they can take huge gulps of water to filter, they can swim slowly on the surface to catch zooplankton, or suck up sediments on the bottom to filter out crustaceans and other invertebrates.

4. Toothed Whales which belong to the suborder Odontoceti, include the Sperm, Killer, Pilot, and Beluga, Dolphin, Porpoises, and etc. Toothed Whales are active hunters eating penguins, squid, fish, seals.

5. Whale Behavior Whale reproduction is totally internal and the gestation period can last from 11 to 18 months. The mother whale and her baby have an extremely close bond and the baby stays with its mother for years. Dolphins are the only animal (besides humans) known to have sex for fun, outside of mating season. Whales breath through a hole in the top of their heads called a blow hole. Toothed Whales have one blow hole, while Baleen have two. Swimming- the whale is a very powerful swimmer, the killer whale is the fastest of all the marine animals.

6. Whales are migratory and travel in pods, it is thought that they travel by current and recognize geological structures. Whales are endothermic or warm blooded they can adapt to any water temperature. They also posses a thick layer of fat called blubber. Whales and dolphins communicate through echolocation. They have been recorded communicating through a series of clicks and other sounds. They can communicate so well that while hunting in packs they can make plans of attack. Male whales sing during mating season and have series of songs and they vary with different pods and through the generations

7. Seals and Sea Lions Paddle like appendages, torpedo shaped body Classified in the suborder Pinnipedia (meaning feather feet) Include seals, sea lions and walruses 31 different species Found all over the world in all seas, walruses are only found in polar regions of the north. Their main source of food are fish and squid, some will eat mollusks, crustaceans, and larger prey.

8. Reproduction of Pinnipeds Have to return to land to mate and give birth Some males acquire harems of females Have evolved the ability to delay the development of their embryos so that they give birth exactly 12 months later when they come ashore again during the regular mating season.

9. Walruses Odobenus Rosmarus Inhabit Sub-Arctic and Arctic regions They eat clams and mussels on the sandy sea floor Males and females have over developed tusks for digging up mussels and pulling themselves up on the ice. Males are bigger to show dominance They can dive more than 90 meters deep

10. Adaptations of Pinnipeds Communicate with a variety of sounds and echolocation They can dive extremely, the elephant seal holds the record of diving 1,500 meters They have a layer of blubber to insulate them They also have a thick coat

11. Sea Otters Enhydra Lutris 3 million years ago became adapted to the water Smallest of marine mammals 1 meter in length Biggest populations are in the pacific coasts of California, Alaska, and the Aleutian Islands They live in kelp forests They are very acrobatically inclined in the water and rarely leave its security

12. The Polar Bear Marine mammal most adapted to land Lives on the ice floes Their hair is hollow which crates a warm air pocket They are mostly solitary animals They eat mostly seal pups or seals and fish, plants, or birds They can smell pray half a mile away Give birth to one or two cubs

13. Manatees and Dugongs Docile marine mammals (Trichechus manatus) Lives in the warm shallow waters of Florida Never leave the water and are herbivores Stay under water for 15 minutes and then resurface for air They are very social and communicate with whistles and squeaks They are also known as the SEA COW Adults consume 45 kilograms of vegetation a day

14. Dugongs Dugong dungon, order sirenians distant relative of the elephant Found in the tropical Pacific (in the rivers and reefs of Australian, Indonesian, and Southeast Asian waters and off the east coast of Africa Tail is triangular unlike the rounded manatee’s

15. Time and Breath in Marine Mammals Sea Otter55m.4-5 min. Porpoise305 m.6 min. Sea Lion168m.30 min. True Seal575m.73 min. Sperm Whale2,200m.90min.

16. Diving Adaptations in Marine Mammals They can exhale and inhale very quickly Higher amount of red blood cells than non- diving mammals They possess extra hemoglobin and myoglobin in their muscles which holds onto oxygen They possess the ability to cause bradycardia which means a slower heart rate when they dive deep