Chapter 9: Marine Reptiles, Birds, and Mammals - PowerPoint Presentation

Slide1

Chapter 9: Marine Reptiles, Birds, and MammalsSlide2

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.Slide3

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.Slide4
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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)Slide6

Sea Turtles

Shell, carapace, is fused with their backbone.

Cannot retract their heads into the shell

Legs are modified into flippers for swimming

Warmer watersSlide7

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 daysSlide8

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)Slide9

Green Sea Turtle

Hawksbill Sea Turtle

Black Sea Turtle

Flatback Sea TurtleSlide10

Kemps Sea Turtle

Leatherback Sea Turtle

Loggerhead Sea Turtle

Olive RidleySlide11

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 aggressiveSlide12

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 aggressiveSlide13

Seabirds

Endothermic

Waterproof feathers

Hollow bones

Hard-shelled egg

Spend significant amount of time in marine environment and eat marine organismsSlide14

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 lifeSlide15

Fig. 9.7Slide16

Fig. 9.8Slide17

Frigate BirdSlide18

Shorebirds

Wading, do not have webbed feet

Live inland as well as sea

Plovers, sandpipers, rails, coots, herons, egrets, and even ducks

 Slide19

Marine Mammals

200

m.y.a

Class

Mammalia

Endotherms

Hair, mostly viviparous (embryo receives nutrients and oxygen through the placenta), mammary glandSlide20

Pinnipeds – Order Pinnipedia

Paddle-shaped flippers for swimming

Predators, fish and squid

Streamlined bodies

Coldwater, thick layer of fat (blubber)

Breed on landSlide21

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 lionSlide22
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Walrus

(

Odobenus rosmarus

)

Tusks are used for defense

Feeds on invertebrates that it sucks up from the sea bottom

Dependent on sea ice

Odobenus rosmarusSlide24

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 bedsSlide25
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Polar Bear

(

Ursus maritimus

)

Semi aquatic animals that live in the Arctic and feeds primarily on seals

Depends on sea ice for survivalSlide27

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

)Slide28
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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)Slide30

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 toothedSlide31

Fig. 9.15Slide32

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 krillSlide33
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Toothed Whales,

Odonticeti

80 species

Teeth

Food is swallowed whole not chewed

Blowhole has one opening

Largest toothed whale is the sperm whaleSlide36

Fig. 9.18(Contd.)Slide37

Dolphins tend to be classified by their distinctive beaks

Porpoises have more blunt shorter “noses”.

BottlenoseSlide38

Whaling

Early as 6000 B.C.

Blubber used to make soap and lamp oil

Baleen used for corsets

MeatSlide39

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 whalesSlide40

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)Slide41
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Tab. 9.2Slide43
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Biology of Marine MammalsSlide45

Swimming

Streamline

Use their flippers, tails and flukes up and down

B

lowhole

on the top of their

head

BlubberSlide46

Fig. 9.25Slide47

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

r

eduction

of the blood supply to the

extremities

collapsible

lungs to help prevent the bends

.

slow their heart rate down conserving

oxygen

t

olerance to lactic

acid in their musclesSlide48

Fig. 9.26Slide49

Echolocation

Nature’s Sonar

E

mitting

sound waves and listen for the echoes to reflect back from surrounding

objects

Short

bursts of sharp clicksSlide50

BehaviorSlide51

MigrationSlide52

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. Slide53
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Tab. 9.3