Transcript Leatherback Sea Turtle - Regional School District 17

Dermochelys coriacea
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Leatherback sea turtle
Leatherback turtle
Dermochelys coriacea
 No other known names in English
http://www.mrsmacdonald.net/ocean_marine_reptiles.htm
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Kingdom: Animalia
Phylum: Chordata
Class: Sauropsida
Order: Testudines
Suborder: Cryptodira
Superfamily: Chelonioidea
Family: Dermochelyidae
Genus: Dermochelys
Species: Dermochelys coriacea
http://theseamonster.net/2011/04/leatherback-sea-turtle-nests-increasing-in-florida/
What shows their relationship:
1. Marine turtles – oceanic food
source and spend most of
their lives there
2. Some males never leave the
ocean once out of nest
3. Flippers for limbs
4. Bony carapace and plastron
5. Nest on land
6. Soft-shelled eggs
http://www.dummies.com/how-to/content/swimming-with-sea-turtles-while-scuba-diving.html
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Cosmopolitan – found in ALL oceans
 Widest distribution of all sea turtles (Alaska/Norway to southernmost
tip of New Zealand)
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Can tolerate ocean temperatures down to 0.4oF (32.7oC)
Map shows KNOWN nesting sites (major and minor)
 Nest sites are sandy beaches
http://upload.wikimedia.org/wikipedia/commons/thumb/b/b4/Lieux_pontes_tortues_luth.png/800pxLieux_pontes_tortues_luth.png
http://www.constantinealexander.net/2011/01/05/index.html
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Nektonic species (open ocean):
 Found mostly in the open ocean, fastest moving reptile (22mph)
 Can navigate along the abyssal plain (up to 1,280m (4,199ft))
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Three major, genetically distinct populations
 Atlantic, Pacific, Pacific sub (Malaysia)
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Most extensive migration of any living reptile, up to 6,000 miles
 Purpose – feeding habitats (open ocean) to nesting/mating habitats (near
shorelines)
http://www.sprep.org/factsheets/leatherbacks/index.htm
http://www.sprep.org/factsheets/leatherbacks/index.htm
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Diet - mainly jellyfish (heterotroph –
carnivore)
 Favorite food: lion’s mane jelly
 Also other soft-bodied organisms (tunicates
& cephalopods)
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Tiger sharks occasionally bite off a
limb or eat them
Dive in a cycle that follows dense
layer of plankton & jellyfish
 Shallow at night
 Deeper as sun rises
http://www.care2.com/c2c/groups/disc.html?gpp=1809&pst=546197
http://nongtao-pampzy.blogspot.com/2009/11/report-for-after-midterm.html
http://www.backhandofjustice.com/friday-links-wakeboarding-edition/
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Eggs & hatchlings fall prey to sea
birds, crabs, large fish, raccoons,
mongoose, feral pigs
Eggs are eaten as food in some
countries
http://wwf.panda.org/what_we_do/endangered_species/marine_turtles/asian_marin
e_turtles/background/threats/
http://coastalcare.org/2010/12/legalized-poaching-turtles-eggs-and-playa-ostional-costa-rica/
http://www.superstock.com/stock-photos-images/4179-3705
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Solitary creatures
Congregate only to mate
No known form of communication
Some nesting beaches are visited by only one female
Fish all day long
 Rest 0.1% of their life
 Bask in sun at surface during mid-day while food is deeper
than normal dive range
http://silverfishattack.blogspot.com/2008/12/gallery-of-turtles-international-pt-2.html
http://www.greenpacks.org/2008/08/25/sea-turtles-endangered-marine-life/
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Largest turtle and living
reptile
 Up to 6 ½ feet long, 16 feet
flipper to flipper, up to 2,000
pounds
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“Tear-drop” (most fusiform of
all sea turtles) body shape
 Purpose is for
hydrodynamics – ease of
movement in water
 Flipper appendages for
movement and steering
http://www.oneocean.org/ambassadors/track_a_turtle/biology/index.html
 Only sea turtle with a leather carapace & 5-7
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dorsal ridges (instead of hard shell)
Dorsal ridges for hydrodynamics
Front flippers for swimming – used synchronously
Rear flippers for steering and stopping
Head and limbs non-retractable to aid in fusiform
body shape
http://www.oneocean.org/ambassadors/track_a_turtle/biol
ogy/index.html
 Eye has nictitating membrane to protect
from sand and drying out
 Cusps on mouth for grabbing prey
 Claws on front flippers (males use for
mating)
 Males have a longer tail
http://bcmw.coastal.edu/outreach-education/sea-turtle-anatomy
http://www.science.fau.edu/biology/faculty_staff/Wyneken/ChelonianAnatomy.PDF
http://www.firelily.com/samples/images/mosaic.lily.html
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Skeleton – for support of
muscles and internal organs
 No teeth – keratin beak
 Bone structure of carapace:
MOSAIC of small bones among
soft tendons, instead of large,
flat ribs (like other turtles).
 Allows leatherback to
withstand large amounts of
pressure as they descend to into
deep parts of the ocean.
 Carapace compresses with
increasing pressure
http://people.wcsu.edu/pinout/herpetology/dcoriacea/speciesdescription.html
http://www.science.fau.edu/biology/faculty_staff/Wyneken/ChelonianAnatomy.PDF
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Muscular system –
 Movement, such as
crawling on land and
swimming
http://www.science.fau.edu/biology/faculty_staff/Wyneken/ChelonianAnatomy.PDF
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Gastrointestinal
system
 Digestion
 Removal of wastes
 Cloaca is the
universal “outlet”
for wastes and also
where females are
fertilized
http://www.science.fau.edu/biology/faculty_staff/Wyneken/ChelonianAnatomy.PDF
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Respiratory system
 Taking in oxygen
and getting rid of
CO2
 DIVE REFLEX –
▪ Slows heart and
shunts blood away
from extremities to
conserve oxygen
during deeper dives
NERVOUS SYSTEM –
 Brain (very small) and nerves – reflex responses and
communication throughout the body for homeostasis
 CIRCULATORY SYSTEM
 Heart, arteries, veins – transport oxygen, carbon
dioxide, nutrients, wastes
 Countercurrent heat exchange – redirects heated
blood back to body core to prevent heat loss in
extremities (reason why leatherbacks can tolerate
colder waters)
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http://www.seaworld.org/infobooks/KillerWhale/adapaqkw.html
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COUNTERSHADED
 Black with spots on carapace, white on bottom
(plastron)
 Countershading allows for camouflage in the
pelagic water column
http://www.indonesiatraveling.com/National%20Parks%20Indonesia/reptiles_indo/pages/dermochelyscoriacea.htm
http://www.care2.com/c2c/groups/disc.html?gpp=1809&pst=546197
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Eat mainly jellyfish
 Has cusps (tomium) on
mouth to grab food
 Have spikes mouth and
throat to keep food
going down
http://www.turtlejournal.com/?p=304
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Mode of movement –
 Leatherbacks ‘flap’ their front flippers to ‘fly’ through the ocean and use
their rear flippers to steer and stop.
 They cannot swim backwards
 They can also use their flippers to ‘walk’ or pull themselves across land
 Swimming, flippers used together
http://www2.scholastic.com/browse/article.jsp?id=3745919
 Walking, flippers alternate
http://whatgives365.wordpress.com/2010/10/23/save-the-sea-turtles-for-petes-sake/
http://rosiemolinary.com/2009/06/01/saving-the-leatherback-turtle-from-extinction/
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Live to be ???????, age of sexual maturity also
unknown
Males and females congregate in coastal, warm
waters to mate
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Females can mate once and lay all nests in one season without
mating again
Females crawl ashore to lay eggs on sandy beaches
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Dig light-bulb-shaped nest with rear flippers (2-3feet deep)
 ~110 leathery-shelled eggs per nest (85% viable)
 2-6 nests per season (from late spring to early fall), 8-12 day
intervals
 Eggs hatch after 60-65 days – hatchlings on their own, only
0.1% survive due to predation by raccoons, feral pigs,
mongoose, crabs, fish, sea birds and humans
http://www.flickr.com/photos/27619014@N04/page4/
Mentioned before
 Spikes in mouth and throat to swallow food
 Dive reflex – able to dive deep and navigate the contours of the
abyssal plains.
▪ Can hold breath up to 30 minutes
 Countercurrent heat exchange – keeps heat in core of body
 Able to swim quickly (22mph)
 SALT GLANDS – remove excess salt from blood and protect eyes from
drying out – people say turtle is crying from leaving eggs behind.
http://weareseaborn.blogspot.com/2011/01/sylvia-earle-saturday-marine-sciences.html
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http://forthepubliceye.wordpress.com/author/forthepubliceye/
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Parts used:
 Mouth, trachea, bronchus, lungs, diaphragm take in air – 50%
lung exchange in one breath (humans = 19%)
 3-chambered heart pumps blood into lungs and rest of body
to carry oxygen rich/oxygen poor blood
SPECIAL ADAPTATION: DIVE REFLEX
http://people.eku.edu/ritchisong/342notes8.html
 Bradycardia – heart beat slows to less than 10% of normal beats per minute
 Peripheral capillaries and veins shut down
 Blood shift – cell membranes allow blood and fluid to pass thru freely to keep
pressure constant and prevent organs from being crushed
 Allows them to dive 30-70 minutes
http://wwf.panda.org/what_we_do/endangered_species/marine_turtles/lac_marine_turtle_programme/
nesting_costarica/gandoca_manzanillo/
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Largest one ever found, >3m and >2,000lb.
Brown adipose tissue (common to cold water
animals) aids in thermoregulation
Unlike other reptiles, can generate own body
heat
Males never leave the water once they enter
Warmer temperatures in nests produce more
females
Evolved over 110 million years ago
http://www.gbrmpa.gov.au/corp_site/info_services/publications/sotr/latest_updates/marine_reptiles/res
ponse
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Eggs are harvested for food – Asian exploitation most significant in
population decline
Humans are biggest cause of Leatherback endangerment.
 Bycatch on trawling boats, drift nets and long lines
 Eaten for their meat
 Turtles eat plastics, mistaking plastic bags for jellyfish
 Nesting beaches are developed, preventing nests and killing
hatchlings by drawing them inland and away from the ocean
TED’s or turtle excluder devices now used on nets
Leatherbacks are protected by Endangered Species Act, CITES
Amendment, and many nest sites are now within National Parks
(Malaysia, Caribbean, Central America)
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"SPREP Factsheet: Leatherback Turtles." Home - Pacific Regional Environment Programme. Web. 19 Apr.
2011. http://www.sprep.org/factsheets/leatherbacks/index.htm
"January 5, 2011." Constantine Alexander's Blog. Web. 19 Apr. 2011.
http://www.constantinealexander.net/2011/01/05/index.html.
"Leatherback Sea Turtle." Wikipedia, the Free Encyclopedia. Web. 19 Apr. 2011.
http://en.wikipedia.org/wiki/Leatherback_sea_turtle.
"SEA TURTLES - Behavior." SeaWorld/Busch Gardens ANIMALS - HOME. Web. 19 Apr. 2011.
http://www.seaworld.org/animal-info/info-books/sea-turtle/behavior.htm.
Wyneken. Charles E. Schmidt College of Science. Web. 04 May 2011. http://www.science.fau.edu/.
"Killer Whales: Adaptations for an Aquatic Environment." SeaWorld/Busch Gardens ANIMALS - HOME.
Web. 04 May 2011. http://www.seaworld.org/infobooks/KillerWhale/adapaqkw.html
"Leatherback Turtle (Dermochelys Coriacea) - Office of Protected Resources - NOAA Fisheries."NOAA ::
National Marine Fisheries Service. Web. 04 May 2011.
http://www.nmfs.noaa.gov/pr/species/turtles/leatherback.htm
"Tidewater Currents - Community Discussion on Care2.com." Care2 - Largest Online Community for
Healthy and Green Living, Human Rights and Animal Welfare. Web. 04 May 2011.
http://www.care2.com/c2c/groups/disc.html?gpp=1809
"Mammalian Diving Reflex." Wikipedia, the Free Encyclopedia. Web. 05 May 2011.
http://en.wikipedia.org/wiki/Mammalian_diving_reflex