Marine turtle

Marine iguana

Saltwater crocodile

Marine Reptiles

Sea snake

Sea Snakes

Yellow- bellied sea snake

Diversity:• Laticodtidae- krates- 5 species (1 is fw in Solomon

Islands)• Hydrophidae- 54 different species

All derived from Colubrid ancestor; colubrids evolved 40 mya; Laticotids evolved from colubrids 30 mya

Location:• Laticotids- live from east coast India to Japan and come

to the tip of Cape York (Australia)• Hydrophiids- found from south tip of Africa to India to

South East Asian Islands to Japan to north half of Australia

Habitat: • Primarily tropical; coastal estuaries, coral reefs, open sea;

33-36oC

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

Sea Snakes

Adaptations to life in the sea1. Osmoregulation: skin is impermeable to salts;

salts eliminated by sublingual gland2. Developing a flattened paddle-shaped tail and

a laterally compressed body.3. Reduced metabolic rate and increased

tolerance for low oxygen levels4. Lungs- greatly enlarged; hydrostatic organ5. Gaseous exchange - lungs and the skin.

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

Olive Sea Snake

Sea Snakes

Banded sea krates forming mating group

• Largest living crocodilians: 6-7 m long

• Eggs laid and incubated on land• Tropical and subtropical

Saltwater crocodiles

Marine Iguanas

• Marine lizard endemic to 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.

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 groupMostly tropical and subtropical

Order Chelonia- warm to temperate and boreal seas ex. leatherback, ridley's, kemps Order Chelonia-

F. Cheloniidae- green, flatback, hawksbill, loggerhead

F. Dermochelidae- leatherbackreduced shell, dermal bone scutes compose shell

F. Emydidae- diamond back terrapin

Class Reptilia

Hawaii species- green, hawksbill, leatherback, Olive Ridley

Conservation Status

1. Endangered-facing a very high risk of

extinction in the wild

2. Vulnerable -facing a high risk of extinction in

the wild

3. Threatened-close to qualifying in one of the

above categories

1. International Union for the Conservation of Nature (IUCN), also called the World Conservation Union

2. The Convention on International Trade in Endangered Species (CITES)

3. The United States Fish and Wildlife Service.

Class: Reptilia: ReptilesOrder: Chelonia: Turtles and TortoisesFamily: Chelonidae: Marine TurtlesScientific Name: Natator depressusDiet: sea cucumbers, soft corals, jellyfishSize: < 1 m in lengthConservation Status: vunerableHabitat: near continental shelf, shallow, soft bottom sea bedsRange: northern part of Australia

flatback

Class: Reptilia: ReptilesOrder: Chelonia: Turtles and TortoisesFamily: Chelonidae: Marine TurtlesScientific Name: Chelonia mydasDiet: seagrass and algaeSize: ~500lbsConservation Status: threatenedHabitat: high energy ocean beaches, convergence zones in the pelagic habitat, benthic feeding grounds in relatively protected watersRange: throughout world in all tropical and subtropical oceans

Green turtle

hawksbill

Class: Reptilia: ReptilesOrder: Chelonia: Turtles and Tortoises Family: Chelonidae: Marine Turtles Scientific Name: Eretmochelys imbricataDiet: ShellfishSize: 76 - 91 cm (30 - 36 in) Conservation Status: Endangered Habitat: coral reefs, rocky coasts Range: Tropical Atlantic, Pacific and Indian Oceans; Caribbean

Class: Reptilia: ReptilesOrder: Chelonia: Turtles and TortoisesFamily: Chelonidae: Marine TurtlesScientific Name: Caretta carettaDiet: CrustaceansSize: 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

Loggerhead

leatherback

Class: Reptilia: ReptilesOrder: Chelonia: Turtles and TortoisesFamily: Dermochelidae: Marine TurtlesScientific Name: Dermochelys coriaceaDiet: sea jellies and salpsSize: 1500 lbsConservation Status: endangeredHabitat: pelagic waterRange: tropical seas, oceanic islands, Atlantic, Pacific, & Indian Ocean

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

Physiology:

Poikilothermic (cold blooded)Skin has scalesSpeed- 35 mphBreath holding- 2 hrs, when sleeping or restingMaturity- 10-50 yrs for greenCannot retract heads like terrestrial turtlesLacrimal gland- salt secretion (drinks seawater)

Anatomy

Has both internal and external skeleton- provided protection and support for organsFused ribsPowerful sense of smell- find natal beachNo ears, but can perceive low frequency sound and vibrationsMale & female- difference in tail size; males tail extends past rear flippers, females is shorter

Mating- at seaMigration- 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)

Kemps Ridley nesting

Usually nest at night

Front flippers dig pit, rear flippers carve out burrow

Turtle nestCross section

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

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

Leatherback hatching Kemps Ridley hatchlings

Sea grass and Algae- adult green sea turtle

Epiphytes on sea grass,Sponges, fish, crabs, conch- loggerheads (suction feeders)

Gelatinous zooplankton:siphonophoresjellyfish

Crustaceans, mollusks, echinoderms- Ridley

Eggs- skunks, raccoons, pigs, lizards, crabs, ants, beetles, fungal and bacterial infections

Hatchlings- birds, mammals, crabs

Adults- sharks, humans

Hawaii- 100-350 nesting femalesFrench Frigate Shoals in the Northwest Hawaiian chain

A. HuntersB. FisheriesC. Marine DebrisD. Coastal Development and Habitat DegradationE. Fibropapilloma

• 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

Increase sea turtle populations:Ranching- eggs or hatchlings from wild populationsFarming- originally from wild populations, for breeding stock

Law enforcement- in Hawaii, turtles protected under Endangered Species ActRiding or harassing- $100,000 fine + prison timeBringing turtle products into Hawaii- $20,000 + prison time

Fishing regulations- Shrimp Trawlers - incidental catch by commercial shrimp fish nets: drowned 10,000 turtles each yearDrift nets, gill nets Turtle Excluder Device (TED)

Catch Statistics (1987) FAO yearbook on Fishery Statistics3100 metric tons

Western Central Atlantic- 1200Eastern Central Pacific- 864South East Pacific- 305Western Central Pacific- 258North West Pacific- 190Eastern Central Atlantic- 153Eastern Indian Ocean- 50Western Indian Ocean- 37Mediterranean - 20South East Atlantic- 10

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

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

Turtle Excluder Device