1. Marine mammals Characteristics of marine mammals: Warm-blooded
Breathe air
Have hair (or fur) can be minimized
Bear live young
Females have mammary glands that produce milk for their young, high in fat-- diluted

2. Marine mammals: Order Carnivora
All members of order Carnivora have prominent canine teeth
Includes:
Sea otters
Polar bears
Pinnipeds (flipper-footed)
Walrus
Seals
Sea lions/fur seals
California sea lions
Figure 14-17c

3. Differences between seals and sea lions/fur seals
Lack visible ear flaps
Have small front flippers
Have claws
Cannot rotate hind flippers beneath themselves
Scoot on their bellies
Figure 14-18

4. Differences between seals and sea lions/fur seals
Have visable ear flaps
Have large front flippers/Walk
Have no claws ,200 lb
Can rotate hind flippers beneath themselves
Bark Loudly
Walruses- no ear, can rotate flippers
Figure 14-18

5. Marine mammals: Order Sirenia
Sirenian characteristics:
Large body size-- Thick skin
Sparse hair all over body– Flat tail
Vegetarians- Dense swollen bones
Toenails (on manatees only)
No ear flap, or hind limbs
Live 70 years +
Includes:
Manatees
Dugongs

6. Marine mammals: Order Sirenia
Manatees
Fresh or brackish water– Caribbean
Flat tail
No incisors- Split mouth 6 teeth
Give 3, every 2-3 years– 12 months
Dugongs
Shallow bays, swamps, Egypt, Australia
Fluke with points
Nostrils farther back on head
Tusks and solid/non-split mouth
Give 10, every 3-5 years

7. Order Cetacea Cetacean characteristics:
Blowholes on top of skull– Specialized muscles
Skull telescoped (streamlined shape)- Fusiform body shape
Very few hairs– No sebaceous glands
Blubber
Flat tails– Flukes Vestigial hind limbs
Most have a dorsal fin
Short neck– fused cervical vertebrae
Bradycardia
Organs go into Anaerobic respiration
Low Surface area to Volume ratio- less exposed skin

8. Order Cetacea Extra capillaries in the lungs– Lungs collapse
Use 3 times as much of the oxygen from a breath of air as do terrestrial mammals
Can force almost all air out of the lungs when exhaling
Twice as high a concentration of red blood cells
2-9 times as much myoglobin in muscle tissue
Heart rate drops to half its normal rate during long dives
During dives, blood is redistributed-- muscles
High tolerance to lactic acid
High tolerance to carbon dioxide
No sinuses, or external ears Air is compressed- not liquid
Excessive Hemoglobin, RBC (50%) and Myoglobin

9. Cetacea Champions
Elephant seals – to 1500 meters, over 60 minutes, spend 90% of time at sea diving
Emperor penguins – up to 500 meters
Leatherback sea turtles – up to 1200 meters
Sperm whales – up to 2032 meters, regularly staying down for 90 minutes
Cuvier’s beaked whales – up to 2992 meters, stayed underwater 138 minutes

10. Marine mammals: Order Cetacea
Figure 14-20

11. Two suborders of order Cetacea
Suborder Odontoceti (toothed whales)
Echolocation (send sound through water)
Includes killer whale, sperm whale, dolphins, porpoises, and many others
Sexual Dimorphism
Teeth are conical or pointed- eat individual prey
Melon on head- chamber filled with fluid
Asymmetrical Skull
Single Blowhole
3 part sternum

12. Two suborders of order Cetacea
Suborder Mysticeti (baleen whales)
Have rows of baleen plates instead of teeth, Keratin
Includes blue whale, finback whale, humpback whale, gray whale, and many others
Double blow hole
Single boned sternum
Batch feeders
Long range migrations

13. Mysticeti: The baleen Mysticeti whales have baleen instead of teeth
Baleen plates:
Hang as parallel rows from the upper jaw
Are made of keratin
Are used as a strainer to capture zooplankton
Allows baleen whales to eat krill and small fish by the ton

14. Baleen
Figure 14-25

15. BALEEN

16. Families of Whales:
Delphinidae— Cone teeth, larger central, dorsal fin, beak,
Trash bag– dolphins and killer whales
Phocoenidae—smaller, coastal, no beak, small dorsal fin Porpoise
Physeteridae- Largest, spermaceti organ in square head, narrow jaw, head divided into “junk”, asymetrical Sperm whale
Platanistidae- Long flat beak, external teeth, blind, echolocation, Ganges, Indus river, slit blowhole, unfused vertebrae, maxillary bone
Balaenidae- Right, Bowhead, head is 1/3 body, neck completely fused, skimmers, finest, longest baleen, slow swimmers

17. Families of Whales:
Balaenopteridae- Rorquals, largest ever, lunge feeders, throat grooves, set back dorsal fins, Fin, Blue whale, Humpback, Sei
Eschrichtiidae– Gray whales, sift food off the bottom, intermediate group, coarsest and shortest baleen, knobs on the back, slight curve to the jaw
Monodontidae– Small, no dorsal fin, artic, Narwhal
Kogiidae- Pygmy sperm whale, smaller, square head,
Platanistoidea: Superfamily- South Asian river Dolphin, Pink. Freshwater, 4 species
Ziphidae– Reversed sexual dimorphism, beaked, 2 front teeth

18. Differences between dolphins and porpoises
Dolphins have:
An elongated snout (rostrum)
A sickle-shaped (falcate) dorsal fin
Teeth that end in points
Killer whale jawbone
Figure 14-22

19. Generation of Odontoceti echolocation clicks
Figure 14-23

20. Odontoceti echolocation
Sound is bounced off objects to determine:
Size
Shape
Distance
Internal structure
Figure 14-24

21. Types of baleen whales Baleen whales include three families:
Gray whale (a bottom-feeder with short baleen)
Rorqual whales (medium-sized baleen)
Balaenopterids (blue whales, finback whales, and other large whales )
Megapterids (humpback whales)
Right whales (surface skimmers with long baleen)

22. An example of migration: Gray whales
Gray whales undertake the longest annual migration of any mammal:
Spend wintertime in birthing and breeding lagoons in Mexico
Spend summertime feeding in highly productive Arctic waters
Figure 14-27