2Marine Iguanas Marine lizard endemic to Galapagos islands These are the only marine lizards.They return to land to escape predators.Marine iguanas have flattened tails that assist them in swimming.Their primary diet are algae that encrust the rocks around the islands.
3Iguanas 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.
4Recently, iguanas have been observed feeding on terrestrial vegetation. The stresses of El Nino may have driven them to forage ashore.Sea turtles, saltwater crocodiles, sea snakes, and marine iguanas are the only surviving reptiles that depend on the sea.
5Sea Snakes Called a krait Snakes are cold-blooded (poikilotherms). Consequently, their distributions are restricted to warm waters.Sea snakes are only found in the Indo-Pacific region.Sea snakes inhabit estuaries, coral reef areas and the open sea and they are often found in large schooling groups.
6Normally, sea snakes are quite docile and don’t 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.
7Behavior:Often schooling in aggregations.Not aggressive but human fatalities have occurred.PreyFeed on small fish or squid, which are killed with powerful venom.
8Predators (few):Sharks, snapper, grouper, crabs, saltwater crocodiles, raptors.They descend to escape.OsmoregulationSkin is impermeable to salts.Salts eliminated by sublingual gland.
9Kraits are oviparous and lay eggs on land Reproduction:Kraits are oviparous and lay eggs on landHydrophiids are viviparous and produce young in the waterNot much known about breedingHowever, olive sea snake breed in spring; seasonal courtship displays
10Saltwater Crocodiles The animal most likely to eat a human Average-size males reach 17 feet (5 meters) and 1,000 poundsSpecimens 23 feet long and weighing 2,200 pounds are not uncommon.Eggs laid and incubated on landTropical and subtropicalThey are excellent swimmers and have often been spotted far out at sea.
11Classic opportunistic predators. Lurk patiently beneath the surface near the water's edge, waiting for potential prey to stop for a sip of water.They’ll feed on anything they can get their jaws on, including water buffalo, monkeys, wild boar, and even sharks.
12HabitatMost commonly found on the coasts of northern Australia, and on the islands of New Guinea and Indonesia.Saltwater crocodiles tolerate salinity and are found mostly in coastal waters or near rivers.They are also found in freshwater near rivers and swamps.Juveniles are raised in freshwater rivers during the wet season between November and March.
13Feeding Behavior Saltwater crocodiles have a variety of prey. Juveniles are restricted to small insects, amphibians, reptiles, crustaceans, and small fish.Adults feed on crabs, turtles, snakes, birds, buffalo, shark, wild boar, and monkeys.Saltwater crocodiles hide in the water exposing only their eyes and nose.They lunge at prey, often killing it with a single snap of the jaws, then drag the prey under water where it is more easily consumed.
14ReproductionSaltwater crocodiles breed in fresh water during the wet season.Males mark their territory and defend it against other males.Males unable to defend their territory are either killed or forced to find another river system.Females reach sexual maturity between years old followed by males that reach sexual maturity at 16 years.The females lay between eggs on average, but can lay as many as 90 at one time.
15She places her eggs and buries them in nests of vegetation and mud which are elevated to avoid loss from flooding during the rainy season.Females protect their nests until the eggs are hatched in 90 days depending on nest temperature.Sex is also determined by nest temperature—males are produced around 31.6°C (88.9°F).Any deviation from that temperature will result in a female hatchling.Once the female hears the newborn call, she digs up the nest and carries her offspring back to the water in her mouth watching them until they learn to swim.
16Marine TurtlesThe first turtles appeared during the Triassic period, 245 to 209 million years ago.The earliest known sea turtles appear in the fossil record in the Late Jurassic period, 208 to 144 million years ago.Scientists believe that modern sea turtles are derived from marsh-inhabiting ancestors that lived during the Late Triassic period.
17Fossil records show that the now-extinct sea turtle Archelon ischyros, which lived 65 to 144 million years ago, was one of the largest turtles that ever lived.It reached a length of 3 to 4 m ( ft.).
18Taxonomy Class – Reptilia Order – Testudines This order includes all turtles and tortoises.It is divided into three suborders:Pleurodira (side-necked turtles),Cryptodira (freshwater turtles, snapping turtles, tortoises, soft-shelled turtles, and sea turtles)Amphichelydia (a suborder of turtles that is now extinct).
19Most scientists recognize two families of sea turtles: Family Cheloniidae includes all sea turtles with scutes (horny plates) covering their shells.Family Dermochelyidae are scuteless turtles with only one modern species; the leatherback turtle.A leatherback turtle is covered with leathery skin.It is the only marine turtle whose backbone is not attached to the inside of its shell.
20GENUS, SPECIESMost scientists recognize seven species and one subspecies of sea turtles:Green (Chelonia mydas); Sub species -- black or Eastern Pacific green turtle (Chelonia mydas agassizii)Order: CheloniaFamily: ChelonidaeConservation Status: ThreatenedHabitat: Benthic feeding grounds in relatively protected waters.Range: Throughout the world in all tropical and subtropical oceans.Green sea turtle (Chelonia mydas mydas)Black sea turtle (Chelonia mydas agassizii)
21loggerhead sea turtle (Caretta caretta) Loggerhead (Caretta caretta)Order: CheloniaFamily: ChelonidaeDiet: CrustaceansConservation status: VulnerableHabitat: Coasts, Open seasRange: Temperate and tropical areas of the Pacific, Indian, and Atlantic Oceans.loggerhead sea turtle (Caretta caretta)
22Kemp's ridley (Lepidochelys kempii) Order: TestudinesFamily: CheloniidaeDiet: crabs, fish, jellyfish, and mollusksConservation status: EndangeredHabitat: Open ocean and gulf waters with the females only coming ashore to lay eggs in beach sand.Range: Kemp's ridley sea turtles are found in the coastal waters and bays of the Gulf of Mexico and Atlantic Ocean.
23Olive Ridley Turtle (Lepidochelys olivacea) Olive ridley (Lepidochelys olivacea)Order: TestudinesFamily: CheloniidaeDiet: algae, lobster, crabs, tunicates, mollusks, shrimp, and fishConservation Status: VulnerableHabitat: mainly a “pelagic” sea turtle, but has been known to inhabit coastal areas, including bays and estuaries.Range: Olive ridleys are globally distributed in the tropical regions of the South Atlantic, Pacific, and Indian Oceans.Olive Ridley Turtle (Lepidochelys olivacea)
24Hawksbill (Eretmochelys imbricate) Order: CheloniaFamily: ChelonidaeDiet: ShellfishConservation status: EndangeredHabitat: Coral reefs, rocky coastsRange: Tropical Atlantic, Pacific and Indian oceans; Caribbean
25Flatback (Natator depressus) Order: CheloniaFamily: ChelonidaeDiet: Sea cucumbers, soft corals, jellyfishConservation Status: VulnerableHabitat: Near continental shelf, shallow, soft bottom sea beds.Range: Northern part of Australia
26Leatherback (Dermochelys coriacea) Order: CheloniaFamily DermochelidaeDiet: Sea jellies and salpsConservation Status: EndangeredHabitat: Pelagic waterRange: Tropical seas, oceanic islands, Atlantic, Pacific, and Indian Ocean
27Adaptation to the Marine Environment Physiology:Poikilothermic (cold blooded)Skin has scalesSpeed- 35 mphBreath holding- 2 hrs, when sleeping or restingMaturity yrs for greenCannot retract heads like terrestrial turtlesLacrimal gland- salt secretion (drinks seawater)
28Anatomy:Has both internal and external skeleton- provided protection and support for organsFused ribsPowerful sense of smellNo ears, but can perceive low frequency sound and vibrationsMale & female- difference in tail size; males tail extends past rear flippers, females is shorter.
29Reproduction Mating- at sea Migration- occurs in late spring; female is accompanied by maleGreen sea turtles migrate as far as 800 miles from feeding area to nest in Northwestern Hawaiian IslandsEgg laying behavior- return to same beach (natal beach)
30Usually nest at nightFront flippers dig pit, rear flippers carve out burrowEgg tooth- used to chip away at shellGroup effort to get out of nest- emerge at night (safer) and head towards brightest light
31Clutch size- about 100 eggs & covers pit with sand Leatherback hatchingKemps Ridley hatchlingsClutch size- about 100 eggs & covers pit with sandEgg incubation- 2 months depending upon speciesSex determined by temperature- males lower temp, females higher temp
33Factors Affecting Turtle Population Marine Debris – Plastic bags, soda can plastic rings, fishing line, oil, and tar.Coastal development and habitat degradation – Noise, light, beach obstructions (affecting nesting habitats).
34Fibropapilloma- virus in Green turtles Affects ability to feed, see, move about, or breathMay be due to pollutants, blood parasites, or habitat changeKaneohe Bay (1991)- >50% infected
35Protection and Management Law enforcement – in Hawaii, turtles protected under the endangered Species Act.Riding or harassing turtles - $100,000 fine + prison time.Bringing turtle products into Hawaii - $20, prison time.Fishing regulations –Shrimp Trawlers – incidental catch by commercial shrimp fish nets: drowned 10,000 turtles each year.Increase sea turtle populations:Ranching – Eggs or hatchlings from wild populations.The End!!