Transcript Marine Reptiles, Birds, and Mammals

Land vertebrates came from the ocean 350 million years ago
 Descended from bony fish had to adapt to harsher
conditions on land
 Lost structural support for swimming had to develop
crawling & walking (tetrapods-“four-footed”)
A specimen of the Jurassic ichthyosaur Ichthyosaurus intermedius, found in Somerset County, England. Photo by Sara Rieboldt, © UC Museum of
Paleontology.
 Tetrapods “four footed” are air breathers
 They evolved from fishes that had lungs & ways to keep from drying out
 Amphibians never really solved this problem
that is why they lay eggs in moist
environments & none are strictly marine
 Reptiles solved the problem of water loss,
truly adapted to living on land, and evolved
from now-extinct amphibians
 Birds and mammals both evolved from
different groups of now-extinct reptiles
 Some reptiles, birds & mammals have
reinvaded the ocean
 7,000 living species including lizards, snakes, turtles,
and crocodiles
 Dry skin covered w/scales to prevent water loss
 Leathery eggshells prevent desiccation, so can lay
eggs on land
 Poikilotherms and ectotherms – “cold-blooded”
 Activity & metabolic rate depends on temperature
of environment
 Sluggish in cold, stay away from cold regions
 Stay away from land where temperatures fluctuate
& stay in ocean where temperatures are constant
 Ancient group of reptiles, body enclosed in shell (carapace)
fused w/backbone
 Cannot retract head into shell
 Large forelimbs are modified into flippers
 9 species that live in warm waters
 All return to land to reproduce & migrate long distances to lay eggs
on remote sandy beaches
 Sea turtle laying eggs videos
 http://www.youtube.com/watch?v=eJP3RxzuHCo
 http://www.youtube.com/watch?v=t-KmQ6pGxg4
 Large Head with powerful jaws
 The adult loggerhead has a reddish-brown carapace and a yellow
plastron. An adult loggerhead weighs 170 to 500 pounds and is
up to 45 inches long. Scientists believe that they are long lived
and could live to 50 years or more.
 The loggerhead is the most common sea turtle in southeastern
U. S. They nest along the Atlantic coast of Florida, South
Carolina, Georgia, and North Carolina and along the coast of the
Gulf of Mexico. The east coast of Florida is one of the two most
important places in the world for loggerhead nesting
 Juveniles and adults eat mostly bottom dwelling invertebrates
such as whelks, other mollusks, horseshoe crabs, and sea
urchins. Their powerful jaws are designed to crush their prey.
Green turtles
 Gets its name from the green-colored fat tissue
under its shell.
 Found in coastal waters in tropics
 Lack teeth but have strong biting jaws
 Green turtles gather to nest on east coasts of
Central America, Northern Australia, Southeast
Asia, Ascension Island & other locations
 Shell grow to 1 meter & mostly eat seagrasses and seaweeds
Leatherback
 Gets its name from tough, oil-saturated, rubbery skin, which is
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strengthened by a mosaic of small bones beneath the skin. This
gives the turtle a leathery appearance and feel. (shell is not solid)
Largest at 2 m (7 ft) and weighs 540kg (1,200 lbs)
Live in open water rarely seen except laying eggs on beaches
Deep divers-2100 ft down
Eat jellyfish
Endangered!
Hawksbill
 Gets its name from its beak-like mouth
 Reddish-brown with yellow streaks
 Adults are usually 30-36 inches long and weigh 100-200 pounds.
Their carapace is covered in thick overlapping scales that are called
scutes
 Hawksbill turtles primarily live in the tropics and subtropics of
the Atlantic, Indian, and Pacific oceans. They are most often
found in coral reef habitats.
 Eats encrusting animals (sponges, sea squirts, & barnacles) &
seaweeds
 Richard M. Kemp, the fisherman who first described these
sea turtles in Florida.
 Their wide, almost round carapace is olive gray, and their
plastron is white to yellowish.
 Kemp’s ridley sea turtles live primarily in the coastal waters
and bays of the Gulf of Mexico and the northern Atlantic
Ocean.
 Kemp’s ridley turtles live their first years well offshore in
the Gulf of Mexico, where they feed on small animals and
plants they find in the mats of floating algae. After
returning to shallow coastal areas, crabs become their
preferred food.
 Marine biologist have tagged green turtles to map
migration to feeding grounds
 2 month journey & 1360 miles along the coast of
Brazil
 Not sure how they find their way, but evidence of
sensing earth’s magnetic field
 Return to nesting area every 2-4 years against
currents
 Females return to same beach where they were
born
 Copulating pairs seen offshore, but only females
venture on shore usually at night
 Biologist tag mostly females because easier to tag
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organisms on land
When laying eggs, females excavate a hole using their
flippers, lay 100-160 eggs, and cover eggs w/sand
Eggs hatch after 60 days
Babies dig out of the sand crawl to the water
Eggs eaten by dogs, ghost crabs, wild pigs & other
animals
Hatchlings easy prey for crabs & birds during the day
While in the water taken by variety of fish & seabirds
 http://www.youtube.com/watch?v=t1kFiehGh9s
 http://www.youtube.com/watch?v=dlGuR6mxAjw
 Sea turtle and Tiger Shark
 http://www.youtube.com/watch?v=Q_D51Ui_XMI
 http://www.conserveturtles.org/satellitetrackingmap.
php?page=satfl_caroline
 Required on all US Shrimp Boats
 Allows turtles to escape net if
caught
 http://video.nationalgeographic.com/video/turtle-
excluder
 Tropical Indian & Pacific oceans
 Laterally flattened, tail paddle-shaped & 3-4 ft. long
 Total marine existence & ovoviviparous (birth live young)
 Few come on shore to lay eggs
 Carnivores-feed on bottom fish & few on fish eggs
 Closely related to cobras
 Venomous & can be fatal to humans (swimmers who step on
them & fishers removing them from nets)
 Rarely aggressive & mouth too small to get good bite
 Hunted for skins & some have become rare
 Marine iguana (Galapagos Islands) spend most of time
basking in sun on land
 Eats seaweeds & dive 33 ft to graze
 crocodile are marine (salt-water) inhabits mangrove swamps
& estuaries along the coast
 Known to venture into open sea
 Largest ever recorded is 33 ft, but rarely over 20 ft
 Most aggressive & known to attack people
 More feared than sharks
 Virus that causes benign tumors
 Homeotherms- “warm-blooded” & endotherms
 Live in variety of environments
 Waterproof feathers for insulation provided by oil
glands above the base of their tail help conserve body
heat
 Preening helps apply the oil to their feathers
 Light hollow bones help for flight
 Eggs covered by hard shell more resistance to water
loss
 Breed in large colonies
 Mostly predators
 Seabirds significant portion of life at sea & feed on
marine organisms
 Most nest on land in large colonies w/mate as life long pairs &
take care of young
 Webbed feet for swimming
 Predators of fish, squid, bottom invertebrates, other small
marine organisms
 Voracious appetites to supply energy needed for flying
 Flightless, w/wings modified into stubby flippers for
swimming
 Denser bones reduces buoyancy making diving easier
 Streamlined bodies w/powerful strokes of wings
makes excellent swimmers
 Can jump out of water & cover long distances by
alternating swimming & jumping Clumsy on land &
nearsighted (eyes adapted for underwater vision)
 Protected from cold by layer of fat under skin
 Dense, water-proof feathers trap air warmed by body
heat
 All but 1 of 18 species live in Antarctica and other
colder temperate regions of S. Hemisphere
 The Galapagos penguin which lives at Equator but confined to
region with cold currents
 Emperor penguin hunts fish & squid while most small
penguin (Adelie) eat krill Strong beaks like seabirds
 Some migrate seasonally between feeding grounds at sea and
nesting areas on land or ice
 Establish breeding colonies
 mate for life
 Male incubates one large egg on ice during the Antarctic
winter while female leaves to feed as soon as she lays egg
 Male hold egg on top of feet for 64 days while huddling close
together protecting themselves form the cold & storms
 Lay eggs at the coldest time so that hatching occurs during
the productive summer when food is most plentiful
 When egg hatches female returns and regurgitates food for
chick
 Then both parent take turns feeding
 When parents feeding chick herded into groups guarded by
few adults (babysitters)
 Returning parent identify chick by voice & appearance
 Feeding takes place for 5 ½ months
 Have tube-like nostrils & heavy beaks that usually
curve at tip
 Months –years on open ocean
 Have salt glands (like turtles & other sea birds) get rid
of excess salt emptying into nostrils
 Albatrosses (wing span up to 11 ft), shearwaters,
petrels
 Skillful flyers catching fish at the surface & some feed
on dead birds or whales
 Mate for life & perform
elaborate courtships
and greeting behaviors
 Nest on remote islands,
on cliffs that are
inaccessible to
predators
 Incubation & care of
single chick takes 8
months or longer
 Breed on islands
around Antarctica then
migrate to Arctic to
feed
 Webbing between all four toes for swimming
 Relatively large fish eating w/large distribution
 http://www.youtube.com/watch?v=krrQjPZOCoY
 https://www.youtube.com/watch?v=D8vaFl6J87s
 Pouch below large beak
 Brown pelican plunge into water & catch fish in pouch
 Diminishing population along coast of United States because
of pesticide pollution
 Has made come back because of restrictions on manufacture & use of
pesticides
 Black, long-necked seabirds dive & pursue prey
 Low flights over water & float low in water (only neck above
surface)
 Narrow wings w/long
forked tail
 Force other seabirds to
regurgitate fish in
midair or catch prey
from surface
 Agile pirates seldom
enter water, not even to
rest because feathers
are not water proof
 Nest in large colonies
 Build messy nest
w/twigs & anything
else they can find