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Marine Turtles (Honu)

Marine Turtles (Honu). History. Found in fossil record 200 mya (Triassic) Common in Cretaceous ( 130 mya ) Present day genera originated 60 (Eocene) and 10 mya (Pleistocene) Not a very diverse group Mostly tropical and subtropical. Taxonomy. Class Reptilia.

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Marine Turtles (Honu)

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  1. Marine Turtles (Honu)

  2. History Found in fossil record200 mya(Triassic) Common in Cretaceous(130 mya) Present day genera originated60(Eocene)and10 mya(Pleistocene) Not a very diverse group Mostly tropical and subtropical

  3. Taxonomy Class Reptilia Order Chelonia- warm to temperate and boreal seas ex. leatherback, ridley's, kemps Order Chelonia- F. Cheloniidae-green, flatback, hawksbill, loggerhead F. Dermochelidae- leatherback reduced shell, dermal bone scutes compose shell F. Emydidae- diamond back terrapin Hawaii species- green, hawksbill, leatherback, Olive Ridley

  4. Conservation Status • International Union for the Conservation of Nature (IUCN), also called the World Conservation Union • The Convention on International Trade in Endangered Species (CITES) • The United States Fish and Wildlife Service. • Endangered-facing a very high risk of extinction in the wild • Vulnerable -facing a high risk of extinction in the wild • Threatened-close to qualifying in one of the above categories

  5. Flatback Class:Reptilia: Reptiles Order:Chelonia: Turtles and Tortoises Family:Chelonidae: Marine Turtles Scientific Name:Natator depressus Diet:sea cucumbers, soft corals, jellyfish Size:< 1 m in length Conservation Status:vunerable Habitat:near continental shelf, shallow, soft bottom sea beds Range:northern part of Australia

  6. Green turtle Class: Reptilia: Reptiles Order: Chelonia: Turtles and Tortoises Family: Chelonidae: Marine Turtles Scientific Name: Chelonia mydas Diet: seagrass and algae Size: ~500lbs Conservation Status: threatened Habitat: high energy ocean beaches, convergence zones in the pelagic habitat, benthic feeding grounds in relatively protected waters Range:throughout world in all tropical and subtropical oceans

  7. hawksbill Class: Reptilia: Reptiles Order: Chelonia: Turtles and Tortoises Family: Chelonidae: Marine Turtles Scientific Name:Eretmochelys imbricata Diet: Shellfish Size:76 - 91 cm (30 - 36 in) Conservation Status: Endangered Habitat: coral reefs, rocky coasts Range: Tropical Atlantic, Pacific and Indian Oceans; Caribbean

  8. Loggerhead Class: Reptilia: Reptiles Order: Chelonia: Turtles and Tortoises Family: Chelonidae: Marine Turtles Scientific Name:Caretta caretta Diet: Crustaceans Size:76 - 102 cm (30 - 40 in) Conservation Status:Vulnerable Habitat: coasts, open sea Range: Temperate and tropical areas of the Pacific, Indian and Atlantic Oceans

  9. leatherback Class: Reptilia: Reptiles Order: Chelonia: Turtles and Tortoises Family: Dermochelidae: Marine Turtles Scientific Name: Dermochelys coriacea Diet: sea jellies and salps Size: 1500 lbs Conservation Status: endangered Habitat: pelagic water Range: tropical seas, oceanic islands, Atlantic, Pacific, & Indian Ocean

  10. reduced shell, • dermal bone scutes • compose shell • 7 dorsal and 5 • ventral dermal bones

  11. Adaptation to the Marine Environment Physiology: Poikilothermic (cold blooded) Skin has scales Speed- 35 mph Breath holding- 2 hrs, when sleeping or resting Maturity- 10-50 yrs for green Cannot retract heads like terrestrial turtles Lacrimal gland- salt secretion (drinks seawater)

  12. Anatomy Has both internal and external skeleton- provided protection and support for organs Fused ribs Powerful sense of smell- find natal beach No ears, but can perceive low frequency sound and vibrations Male & female- difference in tail size; males tail extends past rear flippers, females is shorter

  13. Reproduction Mating- at sea Migration- occurs in late spring; female is accompanied by male Green sea turtles migrate as far as 800 miles from feeding area to nest in Northwestern Hawaiian Islands Egg laying behavior- return to same beach (natal beach)

  14. Kemps Ridley nesting Usually nest at night Front flippers dig pit, rear flippers carve out burrow

  15. Egg tooth- used to chip away at shell Group effort to get out of nest- emerge at night (safer) and head towards brightest light Artificial lights- confuse hatchlings Turtle nest Cross section

  16. Leatherback hatching Kemps Ridley hatchlings Clutch size- about 100 eggs & covers pit with sand Egg incubation- 2 months depending upon species Sex determined by temperature- males lower temp, females higher temp

  17. Prey

  18. Prey Sea grass and Algae- adult green sea turtle Epiphyteson sea grass, Sponges, fish, crabs, conch-loggerheads (suction feeders) Gelatinous zooplankton: siphonophores jellyfish Crustaceans, mollusks, echinoderms-Ridley

  19. Predators Eggs- skunks, raccoons, pigs, lizards, crabs, ants, beetles, fungal and bacterial infections Hatchlings- birds, mammals, crabs Adults- sharks, humans

  20. Factors Affecting Green Sea Turtle Population Hawaii-100-350 nesting females French Frigate Shoals in the Northwest Hawaiian chain • Hunters • Fisheries • Marine Debris • Coastal Development and Habitat Degradation • Fibropapilloma

  21. Commercial Value • Meat • Eggs- nearly forbidden in all countries • with nesting beaches • Soup • Jewelry • Leather Convention on International Trade in Endangered Species (CITES): turtle commerce prohibited in countries that signed agreement

  22. Protection and Management Law enforcement- in Hawaii, turtles protected under Endangered Species Act Riding or harassing- $100,000 fine + prison time Bringing turtle products into Hawaii- $20,000 + prison time Fishing regulations- Shrimp Trawlers - incidental catch by commercial shrimp fish nets: drowned 10,000 turtles each year Drift nets, gill nets Turtle Excluder Device (TED) Increase sea turtle populations: Ranching- eggs or hatchlings from wild populations Farming- originally from wild populations, for breeding stock

  23. Catch Statistics (1987) FAO yearbook on Fishery Statistics 3100 metric tons Western Central Atlantic- 1200 Eastern Central Pacific- 864 South East Pacific- 305 Western Central Pacific- 258 North West Pacific- 190 Eastern Central Atlantic- 153 Eastern Indian Ocean- 50 Western Indian Ocean- 37 Mediterranean - 20 South East Atlantic- 10

  24. Marine Debris- plastic bags, soda can plastic rings, fishing line, oil and tar Costal development and habitat degradation- noise, light, beach obstructions- affect nesting habitat

  25. Fibropapilloma- virus in Green turtles Affects ability to feed, see, move about, or breath May be due to pollutants, blood parasites, or habitat change Kaneohe Bay (1991)- >50% infected

  26. Turtle Excluder Device

  27. Inquiry • What is a natal beach? • What advantage is there in turtle hatchlings leaving in a group rather than individually? • Are the consequences for harassing a turtle adequate? • How does the fibropapilloma virus effect green sea turtles? • What is a TED? How do marine turtles regulate salt in their body?

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