1. Marine Mammals

2. Marine Mammals Order Cetacea Whales, dolphins, porpoises
90 species – 85 marine, 5 freshwater (dolphins)
Front flippers, tail, no rear limbs
Streamlined for efficient swimming
Example of convergent evolution

3. Marine Mammals
Order Cetacea
Blubber
Blowhole on dorsal surface

4. Marine Mammals Order Cetacea Mysticeti (Baleen Whales) – 11 species
Baleen plates attached to upper jaws
Made of keratin

5. Marine Mammals
Order Cetacea
Mysticeti (Baleen Whales) – 11 species

6. Marine Mammals
Order Cetacea
Mysticeti (Baleen Whales) – 11 species

7. Marine Mammals Order Cetacea Mysticeti (Baleen Whales) – 11 species
Rorqual whales – 6 species
Bryde’s, Blue, Fin, Humpback, Minke, Sei
Large blue whales may enclose up to 17,500 gallons (70 tons) of water in one gulp
Blue whales eat kg of food each day!
Short baleen, small dorsal fin, ventral grooves
Right whales – 4 species
Bowhead, Northern Right, Southern Right, Pygmy Right
Long, fine baleen, no dorsal fin, no ventral grooves
Gray whale – 1 species
Short coarse baleen, no dorsal fin, 2-5 ventral grooves

8. Marine Mammals
Order Cetacea
Mysticeti (Baleen Whales) – 11 species

9. Marine Mammals Order Cetacea Odontoceti (Toothed Whales) – 66 species
Teeth adapted for a different diet
Only have 1 blowhole

10. Marine Mammals Order Cetacea Odontoceti (Toothed Whales) – 66 species
Teeth adapted for a different diet
Only have 1 blowhole
Sperm whales – 3 species
Sperm, Dwarf Sperm, Pygmy Sperm
Bulbous head contains spermaceti (waxy substance) that may function in buoyancy and sound generation
Sperm can dive to 3000 m and stay under water for up to two hours!
Feed on fishes and squids, esp. giant squids
Produce ambergris, undigested material in stomach

11. Marine Mammals Order Cetacea Odontoceti (Toothed Whales) – 66 species
Beaked, Beluga, False Killer, Narwhal, Orca, Pilot
Most common in cold water
Dolphins & Porpoises – 33 species
Distinctive beak
Travel in pods

12. Marine Mammals Order Cetacea Odontoceti (Toothed Whales) – 66 species
Beaked, Beluga, False Killer, Narwhal, Orca, Pilot
Most common in cold water
Dolphins & Porpoises – 33 species
Distinctive beak
Travel in pods

13. Marine Mammals Order Cetacea Status
Whales hunted extensively for centuries
Aboriginal whaling (Eskimos)
Non-aboriginal whaling
Began off New England by late 1600s
1860s – Explosive harpoon introduced
Early 1900s –Antarctic whales hunted
1946 – IWC founded
1972 – US Marine Mammal Protection Act
1985 – IWC moratorium on commercial whaling
Norway, Japan, Iceland still practice whaling
IWC allows aboriginal whaling

14. Marine Mammals
Order Cetacea
Status

15. Marine Mammals Diving Adaptations for long and deep dives
High hematocrit
Muscles rich in myoglobin
Reduction of heart rate
Flexible rib cage
Majority of oxygen in blood and tissues

16. Marine Mammals Echolocation
Common in dolphins, porpoises, toothed whales
May occur in some baleen whales and pinnipeds
Dolphins
Whales
Whales

17. Marine Mammals Migration Baleen whales, pinnipeds
Toothed whales tend not to migrate

18. Marine Mammals
Behavior
Playful behavior
Breeching
Spy hopping

19. Ecology

20. Ecology Population Dynamics
Under favorable conditions populations can grow rapidly

21. Ecology
Population Dynamics

22. Ecology
Population Dynamics