AIM: How are marine reptiles adapted for survival?

There are four groups of marine reptiles alive today: Sea turtles Sea snakes Marine lizards (iguanas) Saltwater crocodiles

Reptiles have dry scaly skin which protects them against WATER LOSS

All reptiles live in warm climates because they are ECTOTHERMIC (cold-blooded animals)

Rather than gills, reptiles have LUNGS to exchanges respiratory gases.

Most reptiles have a three chambered heart except for the crocodilians which have a four chambered heart.

Aquatic reptiles are adapted t o excrete excess amount of salt. They have SALT GLANDS Above their eyes.

These glands secrete very salty tears which help to Wash sand from from their eyes when they move on land.

They also excrete very concentrated Urine allowing them to conserve fresh water.

Fertilization in reptiles is INTERNAL

Yet they lay their eggs On land (external development)

Reptiles were the first organisms to have AMNIOTIC EGGS, which contain a yolk to nourish the young and a leathery case to prevent dehydration.

A large predatory marine reptile is the CROCODILE.

Sea Turtles Some endangered Used for leather, food and to make crafts from the shell Mothers lay eggs on beach and leaves eggs alone. Babies make a dangerous journey to the sea

Unlike alligators which are freshwater, Crocodiles are saltwater and freshwater inhabitants.

Another marine reptile that is dangerous to humans is the SEA SNAKE

Sea snakes are found in the tropical Pacific and Indian Oceans

Sea Snakes produce a venom and prey on small fish.

Their flat body and rudder like tail help them to SWIM efficiently

Sea snakes have a special flap of tissue that covers their NOSTRILS, preventing water from entering the lungs

The lung capacity of sea snakes is great and therefore they can stay underwater for Up to 2 Hours in a single breath!

Another marine reptile is a type of lizard called the MARINE IGUANA

It lives on the Galapagos Islands.

Marine iguana feed on seaweed and algae and when their bodies get cold they Return to land to warm up under the sun!