Dermochelys coriacea

 Leatherback sea turtle  Leatherback turtle  Dermochelys coriacea  No other known names in English

 Kingdom: Animalia  Phylum: Chordata  Class: Sauropsida  Order: Testudines  Suborder: Cryptodira  Superfamily: Chelonioidea  Family: Dermochelyidae  Genus: Dermochelys  Species: Dermochelys coriacea

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

 Cosmopolitan – found in ALL oceans  Widest distribution of all sea turtles (Alaska/Norway to southernmost tip of New Zealand)  Can tolerate ocean temperatures down to 0.4 o F (32.7 o C)  Map shows KNOWN nesting sites (major and minor)  Nest sites are sandy beaches Lieux_pontes_tortues_luth.png

 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))  Three major, genetically distinct populations  Atlantic, Pacific, Pacific sub (Malaysia)  Most extensive migration of any living reptile, up to 6,000 miles  Purpose – feeding habitats (open ocean) to nesting/mating habitats (near shorelines)

 Diet - mainly jellyfish (heterotroph – carnivore)  Favorite food: lion’s mane jelly  Also other soft-bodied organisms (tunicates & cephalopods)  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

 Eggs & hatchlings fall prey to sea birds, crabs, large fish, raccoons, mongoose, feral pigs  Eggs are eaten as food in some countries e_turtles/background/threats/

 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

 Largest turtle and living reptile  Up to 6 ½ feet long, 16 feet flipper to flipper, up to 2,000 pounds  “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

 Only sea turtle with a leather carapace & 5-7 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 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

 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

 Muscular system –  Movement, such as crawling on land and swimming

 Gastrointestinal system  Digestion  Removal of wastes  Cloaca is the universal “outlet” for wastes and also where females are fertilized

 Respiratory system  Taking in oxygen and getting rid of CO 2  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)

 COUNTERSHADED  Black with spots on carapace, white on bottom (plastron)  Countershading allows for camouflage in the pelagic water column coriacea.htm

 Eat mainly jellyfish  Has cusps (tomium) on mouth to grab food  Have spikes mouth and throat to keep food going down

 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  Walking, flippers alternate

 Live to be ???????, age of sexual maturity also unknown  Males and females congregate in coastal, warm waters to mate  Females can mate once and lay all nests in one season without mating again  Females crawl ashore to lay eggs on sandy beaches  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 days – hatchlings on their own, only 0.1% survive due to predation by raccoons, feral pigs, mongoose, crabs, fish, sea birds and humans

 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.

 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  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 minutes

 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 nesting_costarica/gandoca_manzanillo/

 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) ponse

 "SPREP Factsheet: Leatherback Turtles." Home - Pacific Regional Environment Programme. Web. 19 Apr  "January 5, 2011." Constantine Alexander's Blog. Web. 19 Apr  "Leatherback Sea Turtle." Wikipedia, the Free Encyclopedia. Web. 19 Apr  "SEA TURTLES - Behavior." SeaWorld/Busch Gardens ANIMALS - HOME. Web. 19 Apr  Wyneken. Charles E. Schmidt College of Science. Web. 04 May  "Killer Whales: Adaptations for an Aquatic Environment." SeaWorld/Busch Gardens ANIMALS - HOME. Web. 04 May  "Leatherback Turtle (Dermochelys Coriacea) - Office of Protected Resources - NOAA Fisheries."NOAA :: National Marine Fisheries Service. Web. 04 May  "Tidewater Currents - Community Discussion on Care2.com." Care2 - Largest Online Community for Healthy and Green Living, Human Rights and Animal Welfare. Web. 04 May  "Mammalian Diving Reflex." Wikipedia, the Free Encyclopedia. Web. 05 May