1. Marine Reptiles Found in the oceans, but breathe air:
Turtles (Order Chelonia)
Snakes (Order Squamata)
Iguanas (Order Squamata)
Crocodiles (Order Crocodilia)
Saltwater crocodile
Marine turtle
Marine Reptiles (Sea Snakes)
Marine Reptiles include sea snakes, saltwater crocodiles, marine iguanas and sea turtles. Sea snakes are a group of true snakes that have completely adapted their life-histories to live in the sea.
Sea snake
Marine iguana

2. Marine Turtles

3. Anatomy Dorsal shell = carapace Ventral shell = plastron
Head does not retract
carapace
plastron

4. Anatomy
Female- thin tail
Male- large, fleshy tail

5. 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)

6. 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

7. Clutch size- about 100 eggs & covers pit with sand
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

8. Predators

9. Commercial Value Meat Eggs- nearly forbidden in all countries
with nesting beaches
Soup
Jewelry
Leather

10. Protection and Management
Increase sea turtle populations:
Ranching- eggs or hatchlings from wild populations
Farming- originally from wild populations, for breeding stock

11. Protection and Management
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)

12. Turtle
Excluder
Device

13. 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

14. 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

15. Sea Snakes Yellow- bellied sea snake Sea Snakes
Snakes are cold-blooded (poikilotherms). Consequently, their distributions are restricted to warm waters and sea snakes are only found in the Indo-Pacific region. There is concern that if a sea-level canal were constructed across Panama, they could become introduced to the Caribbean.
Sea snakes inhabit estuaries, coral reef areas and the open sea and they are often found in large schooling groups.
Normally, sea snakes are quite docile and donÕt pose a threat to humans. They have powerful venom which they use to incapacitate fishes or squid. Human fatalities have occurred and these are most common when the snakes wash up on beaches and humans handle the reptiles.
They have few natural predators other than sharks, saltwater crocodiles and eagles.
Yellow- bellied sea snake

16. Sea Snakes
Behavior: Often schooling in aggregations; Not aggressive but human fatalities have occurred
Prey: Feed on small fish or squid, which are killed with powerful venom
Predators (few): sharks, snapper, grouper, crabs, saltwater crocodiles, raptors; they descend to escape
Venom: 2-10 times as toxic as that of a cobras

17. Sea Snakes Adaptations to life in the sea
Osmoregulation: skin is impermeable to salts; salts eliminated by sublingual gland
Possess a flattened paddle-shaped tail and a laterally compressed body.
Reduced metabolic rate and increased tolerance for low oxygen levels
Lungs- greatly enlarged.
Gaseous exchange - lungs and the skin.
Developing salt excreting glands under the tongue.
2.Developing a flattened paddle-shaped tail and a laterally compressed body making it an efficient swimmer.
3.Reducing its metabolic rate. Sea snakes are capable of remaining submerged for up to 2 hours by decreasing its metabolic rate and developing an increased tolerance for low oxygen levels. After one breath at the surface, it can dive again. A sea snake also has valve-like flaps over its nostrils to stop water flowing into the lungs.
4.The lungs of sea snakes are greatly enlarged, extending to the base of the tail enabling a large volume of oxygen to be stored in the lungs.
5.Parts of the lung are believed to function as a hydrostatic organ regulating the snake's buoyancy.
6.Gaseous exchange occurs through both the lungs and the skin. Up to 22% of the oxygen is supplied from the sea water through the skin and all excess carbon dioxide is lost into the sea.

18. Sea Snakes Reproduction: Krates are oviparous and lay eggs on land
Hydrophiids are viviparous and produce young in the water
Not much known about breeding
However, olive sea snake breed in spring; seasonal courtship displays
Banded sea krates forming mating group

19. Saltwater crocodiles Largest living crocodilians: 18- 21 ft. long
Eggs laid and incubated on land
Tropical and subtropical
Saltwater Crocodiles
Saltwater crocodiles are the largest of living crocodilians and adults can reach 6-7 m in length. These seagoing animals may travel thousands of miles in the ocean. They are wide-ranging and may move into freshwater areas as well. They havenÕt entirely left land and must return to lay their eggs which are incubated in a terrestrial nest. Their poikilothermic nature means that their distributions are limited to warm areas. Diets include fishes, invertebrates and vertebrates.

20. Marine Iguanas Found on Galapagos islands
Herbivorous: graze on seaweeds
Salt-glands on nose to eliminate excess salt
Recently observed feeding on land for first time
They return to land to escape predators.
Marine Iguanas
These are the only marine lizards and they are endemic to the Galapagos Islands off Ecuador. Marine iguanas have flattened tails that assist them in swimming and they have adapted to an aquatic life. Their primary diet are algae that encrust the rocks around the islands. Iguanas dive to feed on the algae and in the process, their bodies undergo substantial cooling. After diving and feeding bouts, they must warm themselves on land to raise their body temperature. During feeding they accumulate a lot of salt that is excreted via specialized salt-glands on their noses. Recently, iguanas have been observed feeding on terrestrial vegetation. The stresses of El Ni–os may have driven them to forage ashore.