Class Reptilia • Order Chelonia - Turtles • Order Squamata – Snakes and Iguana
Marine Turtles 7 Species • Leatherback • Loggerhead • Flatback • Green • Hawksbill • Kemp’s Ridley • Olive Ridley
Characteristics of Marine Turtles • Larger then land relatives • Cannot retract their heads completely into their shells • Compressed streamlined shell and broad flattened forelimbs to paddle • Weight over 500 kg • Forelimb span over 3m • Amniotic Egg
Behavior of Marine Turtles • Breathe air but spend as much as 3 hours submerged • 6 of 7 species are carnivores feeding on jellyfish, squids, crabs, sponges and fish • Green turtles are herbivores • Generally solitary except for courtship and mating • Found worldwide
Reproduction • Mate at sea • Breeding occurs in cycles that vary from 1-5 years • Female return to the beach they hatched from to lay their eggs • Oviparous • Females usually lay several batches of eggs at 2-3 weeks intervals
Nesting • Occurs at night • Females excavated with hind flippers • Clutch sizes 80-150 eggs • Covers eggs with layer of sand and returns to the sea • Incubation time 2 months • Infants hatch at night and dash for the sea
Migration • Sea turtles migrate hundreds and sometimes thousands of miles from their feeding grounds to their nesting grounds.
Sea Turtles In Danger • Most species are endangered • Beach erosion after commercial development and alteration of beaches for improved boat access has destroyed nesting sites. • Turtles killed when trapped in fishing nets • Hunted for meat, eggs, leather, and shells
Sea Snakes • Snakes are descendants of lizards that have lost their limbs as an adaptation to a burrowing lifestyle. • 50 species that live in marine environment • Most remain close to shore in shallow waters.
Adaptations for Marine Life • Streamlining the body • Scales absent or reduced • Tail is laterally compressed and used as a paddle • Nostrils are higher on the head to aid in breathing while drifting, special valves in nostril to prevent water from entering while submerged
Adaptations for Marine Life • A single lung reaches almost to the tail • Gas exchange through skin when underwater • Lower metabolic rate to consume less O2 while submerged
Feeding • Sea snakes mainly feed on fish and eels • Most species have venomous fangs • Rely on ambush to capture prey • Swallow prey more than twice their diameter • Eyesight is the most highly developed sense • Feed during the day
Reproduction • Only 3 oviparous species (coming to land to lay eggs) • The rest are viviparous (females retaining their eggs within their body until they hatch) • Young can swim and feed immediately • Congregate in enormous numbers
Behavior • Live in the tropical and subtropical Pacific and Indian Oceans • Toxin adapted to killing fish • Timid by nature and rarely bite humans
Dangers • Eaten by humans • In Japan the consumption of sea snakes is so large that it supports a major fishery. • Hunting of skins has led to their near extinction in some areas.
Marine Crocodiles • Several species of crocodile (American & Nile) venture into the marine environment to feed. • Feed on fish, birds and mammals • Saltwater Crocodile best adapted for marine ecosystem lives in India, Asia and Australia • Oviparous – eggs laid in nest on land
Marine Iguana • The only marine lizard • Endemic to the Galapagos Islands • Eats Seaweed (algae) • Oviparous (eggs laid in nest on land)
Characteristics • Average length 1.3m • Black or gray in color except when males are near mating season when they turn shades of red or green • Dark pigment shield them from UV radiation • Long sharp claws permit the lizard to hold fast to lava • Can live up to 30 years
Feeding • Herbivores (algae) • Consumes large amounts of seawater while feeding • Specialized tear and nasal glands to excrete salt
Behavior • Nasal spraying • Good swimmers • Females reach sexual maturity 3-5 years old • Males reach sexual maturity 6-9 years
Reproduction • Females mate once per season • She chooses a site digs a hole and deposits eggs • Guards the nest for 16 days • Incubation takes 89-120 days • Infants hatch and run bipedal to the nearest cover.