1. Mammals  Mammal- Any of various warm-blooded vertebrate animals of the class Mammalia, characterized by a covering of hair on the skin and, in the female, milk-producing mammary glands for nourishing the young.

2. Marine Mammals –Have similar adaptations for the marine environment Body Size Streamlined Shape Insulation –Dense fur or blubber Modified skeleton –Shortening of appendages –Loss of hind limbs Similar Physiological Adaptations –For diving, thermoregulation, osmoregulation, communication and orientation

3. Marine Mammals –Have similar habitat requirements Require the aquatic habitat for survival –They can therefore be used as indicators of habitat degradation. –Many have been exploited by humans to the point of near extinction

4. Types of Marine Mammals –Three Orders Carnivora- The mammalian carnivores, includes cats and dogs –Suborder Pinnipedia (‘fin’-‘footed’) –Other Marine Carnivora »Family Ursidae: Polar Bears »Family Mustelidae: Otters Cetacea- Whales dolphins and porpoises Sirenians- Manatees and Dugongs

5. Marine Carnivora Suborder Pinnipedia (‘fin’-‘footed’) –Most marine of the Carnivora –Use fat and/or fur for insulation –Deep divers –Must return to land in order to give birth –Ex: Seals, Sea lions and walruses

6. Sea Lions Family Otariidae –Sea lions and fur seals –The “Eared Seals” Hind flippers rotate under the body to permit walking or running on land Swim by using the large fore flippers Dense fur that consists of long, coarse hairs and thick underfur in which air is trapped to promote insulation Tend to have a temperate-to-subtropical distribution

7. Sea Lions

8. True Seals Family Phocidae- True Seals –Lack ears, sometimes called “earless seals” Unable to rotate the hind limbs forward under the body and therefore don’t move well on land. –Swim by using the hind flippers. –Small pectoral flippers are used for steering. Blubber is used for insulation Excellent diving abilities Phocids are relatively large compared to Otariids Phocids are found throughout the world’s oceans

9. Seals

10. Walrus Family Odobenidae –Walruses One species, Odobenus rosmarus –Large tusks –Can rotate hind flippers under the body –Use both front and hind flippers to swim –No external ear –Naked skin with only a few sparse hairs

11. Walrus

12. Other Marine Carnivora –Family Ursidae Polar Bears –Found only in the Arctic

13. Other Marine Carnivora Otters –Sea otters of the pacific coast of N.America and Russia –Marine Otter of Chile and Peru Extremely dense fur Flattened hind feet for propulsion in water Axillary flap of skin to hold or store food and tools Horizontally flattened tail

14. Sea Otters

15. Cetaceans Cetacea- Whales dolphins and porpoises –All are large, ranging from 2m to >30m –Streamlined body form with minimal protuberances that could cause drag Ex: They all lack external ears, reproductive organs, appendages and are generally hairless Vestiges of the pelvic girdle Some have hair during fetal development –Elongated skull with overlapping bones –Dorsal positioning of the blowhole –Subdermal blubber that can be 10’s of centimeters thick. –Porous, oil-filled bones

16. Cetacean Evolution Evolved from ariodactyls, even-toed ungulates such as cows or pigs –Multiple stomach compartments Like cows

17. Two Suborders of Cetaceans Mysticeti –Baleen Whales –11 Species Odontoceti –Toothed Whales –64 species

18. Mysticeti Have baleen- a keratin-based brushlike adaptation suspended from the upper jaw Dorsally symmetrical skull Two blowholes Non fused mandible Tend to be large –Smallest mystecete, the Pygmy Right Whale is >6m

19. Mysticeti Families Family Balaenidae –4 Species:N. and S. right Whale, Bowhead and Pygmy Right Whale –Extremely convex profile of upper surface of skull –No dorsal fin –No gular grooves Family Balaenopteridae –6 species: Blue, Fin, Sei, Bryde’s, Minke and Humpback –Flat profile to skull –Small triangular dorsal fin –Numerous gular grooves run from the snout to umbilicus Family Eshrichtiidae –1 species: Gray whale –slightly convex profile to skull –no dorsal fin: aseries of ‘Knuckles” above the audal peduncle –2-4 short gular grooves: benthic feeder

20. Family Balaenidae

21. Family Balaenopteridae Blue Whale Fin Whale Minke Whale Humpback Whale

22. Family Eshrichtiidae Gray Whales

23. Odontoceti (toothed whales) –Possess teeth in one or both jaws. –Dorsally asymmetrical skull –A single blowhole –Fused mandible –Vary in size Some dolphins are <2m The sperm whale is 18m

24. Family Physeteridae 3 Species: Sperm whale, Pygmy and Dwarf sperm whale Dorsal hump or small dorsal fin Large bulbous head with spermaceti organ Flukes notched Well developed conical teeth in lower jaw only, fit into sockets in upper jaw

25. Sperm Whale

26. Family Ziphiidae 18 species: Beaked whales 2 gular grooves Small dorsal fin Slender rostrum (beak) Flukes not notched 1-2 pairs of teeth confined to lower jaw

27. Beaked Whale

28. Family Monodontidae 3 Species: Beluga, Narwal, and Irrawaddy Dolphin Generally no dorsal fin or small dorsal fin Head blunt, no beak Flukes notched All cervical vertebrae free

29. Belugas

30. Family Platanistidae 5 Species: River Dolphins Small dorsal fin Jaws form a long beak Flukes notched Many well developed conical teeth in both jaws

31. River Dolphins

32. Family Delphinidae 32 Species: Dolphins, including the Orca Large dorsal fin (except right whale dolphin) Jaws form a beak or head gibbose (hump) Flukes notched Well developed conical teeth in both jaws or in lower jaw only

33. Dolphins

34. Family Phocoenidae »Porpoises »6 Species: Dorsal fin large and triangular »Head blunt, no beak »Well developed to poorly developed spatulate teeth in both jaws

35. Porpoises

36. Sirenians- Manatees and Dugongs –Evolved from elephants and other subungulates –Skin lacks hair –Well developed vibrissae (whiskers) –Well developed layer of fat –Pectoral limbs modified as flippers –Hind limbs absent –Tail modified into flukes –Ears absent

37. Family Dugongidae 1 Species Dugong dugon Nails absent Tail modified into notched flukes Male and female approximately the same size

38. Dugong

39. Family Trichechidae 3 Species of Manatee Vestigial nails present Tail modified into rounded paddle Male and female approximately the same size

40. Manatees