1. Chapter 9: Marine Reptiles, Birds, and Mammals

2. Vertebrates
350 m.y.a. vertebrates invaded land
Decendents of bony fish
Land vertebrates had to adapt to harsher conditions on shore
Tetrapods had to develop lungs that allowed for absorption of oxygen directly from air.
Tetrapods had to evolve in ways to keep from drying out.

3. Amphibians, early tetrapods, have eggs that are vulnerable
Amphibians, early tetrapods, have eggs that are vulnerable. They need to stay moist and lay them in water.
Reptiles on the other hand solved the problem of waterloss, resulting in the evolution of birds and mammals.
One they were equipped with adaptations for land they reentered the ocean.

5. Classification
Marine Reptiles
7000 species
Dry skin with scales
Eggs leathery shell
Poilkilotherms (body temp varies w/environment) and ectotherms (lose metabolic heat to environment)

6. Sea Turtles
Shell, carapace, is fused with their backbone.
Cannot retract their heads into the shell
Legs are modified into flippers for swimming
Warmer waters

7. Feed on seagrass, seaweed, sponges, sea squirts, barnacles, jellyfish
Must return to land to reproduce
Migrate to original beach, possible use of magnetic fields
Return every 2-4 years, copulate offshore, females come on shore at night, dig a hole lay between 100 – 160 eggs, hatch approx. 60 days

8. 7 (8) species of Sea Turtles (all classified as threatened);
Green (Chelonia mydas)
Hawksbill (Eretmochelys imbricata)
Leatherback (Dermochelys coriacea) D.o.d,largest turtle
Kemp’s Ridley (Lepidochelys kempii)
Loggerhead (Caretta caretta)
Flatback (Natator depressa)
Black (Chelonia agassizii)
Olive Ridley (Lepidochetys olivacea)

9. Green Sea Turtle
Hawksbill Sea Turtle
Flatback Sea Turtle
Black Sea Turtle

10. Leatherback Sea Turtle
Kemps Sea Turtle
Leatherback Sea Turtle
Loggerhead Sea Turtle
Olive Ridley

11. Sea Snakes Approx. 55 species found in tropical waters
Laterally flattened and tail paddle-shaped for swimming, 3-4ft long
Mate in the ocean, ovoviviparous
Closely related to cobras, rarely aggressive

12. Marine Iguana (Amblyrhynchus cristatus)
Galapagos Islands
Eats seaweed and can dive 33ft to graze
Saltwater Crocodiles (Crocodylus porosus)
Mangroove swamps and estuaries
20-33ft long, very aggressive

13. Seabirds
Endothermic
Waterproof feathers
Hollow bones
Hard-shelled egg
Spend significant amount of time in marine environment and eat marine organisms

14. Penguins
Flightless, wings modified into stubby flippers
Bones are denser to reduce buoyancy
Layer of fat and dense waterproof feathers
Feed on fish, squid, and krill
Lay eggs during cold times of year to ensure food availability when egg hatches
Emperor penguin (Aptenodytes forsteri) mate for life

15. Fig. 9.7

16. Fig. 9.8

17. Frigate Bird

18. Wading, do not have webbed feet Live inland as well as sea
Shorebirds
Wading, do not have webbed feet
Live inland as well as sea
Plovers, sandpipers, rails, coots, herons, egrets, and even ducks

19. Marine Mammals
200 m.y.a
Class Mammalia
Endotherms
Hair, mostly viviparous (embryo receives nutrients and oxygen through the placenta), mammary gland

20. Pinnipeds – Order Pinnipedia
Paddle-shaped flippers for swimming
Predators, fish and squid
Streamlined bodies
Coldwater, thick layer of fat (blubber)
Breed on land

21. Seals
Largest group, rear flippers that cannot be moved forward
They move on land with front flippers
Harbor Seals
Elephant Seals
Sea Lions and
Fur Seals
Eared seals
Move rear flippers forward
Use all limbs to walk/run on land
Graceful swimmers
Males much larger than females
California sea lion

23. Walrus (Odobenus rosmarus)
Tusks are used for defense
Feeds on invertebrates that it sucks up from the sea bottom
Dependent on sea ice
Odobenus rosmarus

24. Sea Otter and Polar Bear
Order Carnivora
Sea Otter (Enhydra lutris)
Smallest marine mammal averages between 60 – 80 pounds
Lacks layer of blubber instead uses air trapped in its dense fur
Breed and give birth in water, eats up to 30% of its body weight/day (invertebrates and fish)
Lives in kelp beds

26. Polar Bear (Ursus maritimus)
Semi aquatic animals that live in the Arctic and feeds primarily on seals
Depends on sea ice for survival

27. Manatees and Dugong (sea cows)
Order Sirenia, relatives of elephants
Pair of front flippers, no rear limbs
Paddle – shaped horizontal tail
Blubber, live in shallow coastal waters
Strict vegetarians, large in size Dugongs (10ft) and Manatees (15ft)
Manatee (Trichechus)

29. Whales, Dolphins, and Porpoises
Order Cetacea
Bodies are streamlined, breath air, warm-blooded, have hair, and produce milk for their young
Front flippers, no rear limbs (embryonic stage only)
Many have dorsal fin, muscular tail fin-like (fluke)

30. Blubber, provides insulation and buoyancy
Single or double opening on the top of their head – blowhole
90 species, all marine except 5 freshwater dolphin species
Divided into two groups; toothless and toothed

31. Fig. 9.15

32. Baleen (toothless) whales, Mysticeti
Rows baleen hang from upper jaws made up of keratin
Largest whales, 13 species
Blowhole has two openings
Blue Whale (Balaenoptera musculus)
Largest, males up to 80ft and females up to 110ft
Weigh up to 90 – 140 tons
Feed by gulping up schools of fish and swarms of krill

35. Toothed Whales, Odonticeti
80 species
Teeth
Food is swallowed whole not chewed
Blowhole has one opening
Largest toothed whale is the sperm whale

36. Fig. 9.18(Contd.)

37. Dolphins tend to be classified by their distinctive beaks
Porpoises have more blunt shorter “noses”.
Bottlenose

38. Whaling
Early as 6000 B.C.
Blubber used to make soap and lamp oil
Baleen used for corsets
Meat

39. 1800s
harpoons and steamships made whaling easier
Population decline
whales have long life spans mammals
slow reproductive rate
slow swimmers
Factory ships
Reached it peak in 1930s
Right whales

40. Marine Mammal Protection Act of 1972,
1946, International Whaling Commission (IWC) in attempt to regulate whale hunting
IWC collected data and set annual quotas
Marine Mammal Protection Act of 1972,
US Congress banned the hunting of all marine mammals in the US waters and importation of marine mammal products (except in traditional fisheries of AK natives)

42. Tab. 9.2

44. Biology of Marine Mammals

45. Swimming Streamline Use their flippers, tails and flukes up and down
Blowhole on the top of their head
Blubber

46. Fig. 9.25

47. Diving Adaptations efficient exchange of air on the surface
storage of more oxygen in the blood and muscles as result of high concentration of hemoglobin
reduction of the blood supply to the extremities
collapsible lungs to help prevent the bends.
slow their heart rate down conserving oxygen
tolerance to lactic acid in their muscles

48. Fig. 9.26

49. Echolocation
Nature’s Sonar
Emitting sound waves and listen for the echoes to reflect back from surrounding objects
Short bursts of sharp clicks

50. Behavior

51. Migration

52. Reproduction Delayed implantation (Pinnipeds)
Little is known about cetacean reproduction.
Gestation lasts for 11 to 12 months in most cetaceans.
Calves are born tail first
They can live more than 40yrs.

54. Tab. 9.3