Reptiles : Alligators & Crocodiles Snakes & Iguanas Sea Turtles

1. Reptiles: Alligators & Crocodiles Snakes & Iguanas Sea Turtles Pgs 5-77 thru 5-80

2. Reptile Characteristics • Ecothermic vertebrates • Breathe with lungs • Skin made of scales (no hair; no feathers) • 3 chambered heart • Internal fertilization; lay eggs with soft shells • 1st to see Amniotic Egg • A thin, membranous, fluid-filled sac surrounding an embryo which keeps the embryo from drying out. • Reptiles, birds, & Mammals • Offspring look like its parents • Examples: alligators, crocodiles, turtles, lizards, & snakes

3. Order Crocodilia • Salt Water Crocodile • Grow to 20 feet • Can live in the ocean, but primarily estuaries • American Alligator • largest reptile in N. America. • grow to be 6’-19’. • found in Coastal N. Carolina to Florida, along the southern coast of Texas, and North to SE Oklahoma and Arkansas. Crocodile Alligator

4. How can you tell the difference? Similar… Difference… • Alligators-rounded snout • Crocodile’s mouth is more pointed (triangular shape) & its teeth are visible. • both very large reptiles. • Live near fresh water • When there is a drought an alligator is known to dig a deep hole or “den”, • provides water for the wildlife around them.

5. Order Squamata • Sea Snakes • Have flattened tail to swim • breathe air • Can remain underwater for hours • Venomous • Hunt small fish • Not a major threat to humans b/c fangs are small & back of mouth; less territorial than terrestrial • Can be fatal unless given antivenin

6. Order Squamata • Marine Iguana • Live in the Galapagos island • Herbivore • Live & forage under water • Salt glands on nose to eliminate excess salt

7. Marine Iguana Podcast • http://education.eol.org/podcast/marine-iguana • (~5 min) • 1. What eats a marine iguana? • 2. How do they know when the predator is coming? • 3. What were the observations made by scientists between iguanas and mockingbirds?

8. Order Chelonia • 7 species of marine turtles • 5 common to Florida • Leatherback • Green • Loggerhead • Hawksbill • Kemps Ridley • Olive Ridley • Flatback. • Note * Olive ridley & Flatback turtles not seen in Florida. • All live in warm waters

9. Sea Turtle Nesting • Females return to same the same beach biannually for nesting • only during the summer months • Dig a hole in the sand using front flippers • ~100 ping-pong sized eggs laid/ nest • Nest temperature determines sex of hatchlings • Warmer- females • Cooler- males • Incubation is approximately 2 months • Hatching & emergence can take a couple of days (2 to 3 days) • 1 in 1,000 eggs will survive to adults

10. Marine Turtle Adaptations • Legs • Modified flippers • Move in water & on land • Beaks- no teeth • Can hold breath for up to 3 days by slowing heart rate • Papillae in esophagus • White teeth like structures • Help keep the food down in the stomach.

11. Adaptations continued… • Shell • Carapace (top ) • made up of bony plates • covered by a layer of scales called scutes • Plastron (bottom) • Provides Protection • Excrete excess salt through tear ducts (Lacrimal Gland)

12. Named for it’s abnormally large head. Avg. adult weight is 275 lbs Heart shaped carapace reddish brown on top & creamy yellow underneath 5 lateral scutes Has two claws on each front flipper Diet: clams, crabs and other armored animals. A slower swimmer, it can fall prey to sharks but can travel great distances quickly 1. Loggerhead Turtles

13. Where in FL Can You Find a Loggerhead Sea turtle? • Only species of sea turtle not to be listed as endangered • List as threatened • Most common species found in FL • Approximately 15,000 females nesting here annually Other Florida Counties South Florida Counties

14. 2. Green Turtle • Named for their green body fat • Were valued for their meat, hide, eggs and “calipee” • used for green turtle soup. • Diet: vegetarian species • Habitat: shallow flats & sea grass meadows • Approx 100-1000 Green turtles nest on FL beaches annually

15. Green Turtle • 4 lateral scutes • 1 claw on each front flipper • Avg adult weight is 350 lbs • Oval shaped carapace • olive-brown with darker streaks • plastron is yellow

16. 3. Leatherback marine giants • Avg 6 feet in length • weigh btwn 500- 1500 lbs • Carapace is made up of leathery skin (not bony scutes) • 5 ridges • Black with white, pink and blue highlights in color • No claw on front flippers

17. Nomads of the Sea • Diet: soft-bodied animals (jellyfish) • Use teeth-like Papillae to hold onto food • Rare to FL • Only 30-60 females nest in Fl a year • Able to dive 3,000 feet below • Can travel 3000 miles away from their nesting beaches • They regulate their own body temperature to live in varying global conditions

18. Named after their raptor-like jaw Diet: sponges. Adults weigh bwtn 100-200lbs & are 30 inches long Habitat: lagoons, reefs, bays, & estuaries Atlantic, Pacific, & Indian Oceans Common in Fl. Keys 4. Hawksbill Turtles

19. Hawksbill • Carapace is shaded with black & brown markings on an amber background • Overlapping scutes • 4 lateral scutes • Curved beak with distinct overbite • 2 claws on front flippers

20. Hawksbill Hazard’s • The shell is used to make jewelry, hair decorations and other ornaments

21. Named for Richard M. Kemp a fisherman who submitted the type specimen from Florida The rarest and most endangered sea turtle in the world Avg size is 85-100 lbs 2 to 2.5 feet in carapace length Diet: crabs & other crustaceans Captive breeding attempts for this species not a viable option 5. Kemp’s Ridley

22. Arribadas • Synchronized nesting habits of Ridley turtles • Turtles mate offshore • Females nest 3x per season on the beaches • Mating/nesting continues for a week or so • Triggered by the moon? Pheromones?

23. Human impacts to Sea turtles… • All are endangered or threatened • 1. Habitat degradation • Sea walls & development of houses/hotels • Affects nests • 2. Pollution – oil spills; plastic bags

24. Human impact continued… • 3. Bycatch & entanglement

25. 4. Hunting • Eggs harvested/poached • Shells used in jewerly & decor • 5. Light Pollution • Turtle look for the moon light over water • Hatch and move toward higher ground due to lights on houses

26. What can we do? • Turtle Exclusion Devices (TEDs) • Trapdoors allow larger animals to push themselves out of the net • Only marginally effects the success of the net • ~ 11,000 turtles estimated to have been killed annually in nets prior to TEDs • Kemp’s Ridleys were hardest hit • Nesting activities have increased since TEDs use