Marine Reptiles Class Reptilia

Characteristics of Reptiles Appeared more than 300 million years ago Evolved to be suited for life on land Lungs Leathery egg shell to prevent drying out Ectothermic: “cold blooded” Skin is covered with scales: to prevent drying out

Sea Snakes Family Hydrophiidae Found in Indian and Pacific Oceans Only 55 living species Laterally flattened bodies Flattened tail-like paddle Ability to close nostrils Most are 3 to 4 feet long (1-1.3 m) Most are ovoviviparous: eggs are retained in the mother and give birth to live young. (A few still lay eggs on land.)

Sea Snakes cont. Carnivores Highly poisonous; venom can kill humans (related to cobra) Small mouth and are not aggressive

Marine Iguana Only living marine lizard Found in the Galapagos Islands Basks on lava rocks to stay warm Feed on submerged algae Osmoregulation: excrete salt from a gland in the nose

Order Crocodylia American Alligators are found in freshwater. Avg 800 lbs and 13 feet Found from Eastern TX to Florida Crocodiles are found in freshwater and saltwater Avg 2,000 lbs and 16 feet Found Indian Ocean, Australia and W Pacific Islands Can be found in open oceans

Crocodile vs Alligator

Sea Turtles Characteristics: Carapace: armor-like shell that is fused to their backbone (cannot retract head into shell) paddle-like flippers fatty deposits and light spongy bones increase buoyancy

Nutrition Most found in shallow coastal waters where food is abundant Herbivore: Green Sea Turtle- eat turtle grass Carnivores: loggerheads- crabs, shellfish, sponges, fish, horseshoe crabs; hawksbill-mussels, clams, jellyfish; Kemp’s Ridley- sea urchins and other inverts; leatherbacks- jellyfish in open ocean (pharynx has sharp spines to hold slippery prey.

Migration Travel hundreds of miles away from feeding ground to its nesting beach where they were born every 2-4 years.

Reproduction Mating takes place in the ocean, males do not venture onto the shore only females. 100-160 eggs are buried in the sand because a. porous and can dry out b. protects the eggs from predators c. keeps the eggs at the right temperature eggs hatch after 60 days. Sex depend on temperature incubation (warmer female, cooler male) and hatchlings scurry to ocean and follow currents and float among Sargassum (sea weed) only about 10% survive Depending on the species; some sexually mature around age 4 others around age 15

Kemp’s Ridley

Olive Ridley

Green Sea Turtle

Loggerhead

Leatherback

Hawksbill

Flat Back Turtle

Nesting and Predators What is an arribada? Nesting behaviors? What species use arribada? What are advantages of this behavior? What are disadvantages of this behavior?