4 Life Cycles of Marine Animals Scientists believe that all life on Earth began in the ocean hundreds of millions of years ago Today thousands of different animal species live in and around the ocean No one knows exactly how many different species of marine animals there are hundreds of new species are discovered every year Although they share the same saltwater habitat all marine animals grow and change differently over time Each species has its own unique life cycle Life Cycles All living things have a life cycle An animal’s life cycle begins when it is born and is completed when it has young of its own During their life cycles different species grow and change in different ways Everything an animal does throughout its life cycle happens so that it can survive long enough to reproduce Without this circle of life all living things would become extinct The life cycles of marine animals can be as different as the animals themselves
5 Green Sea Turtles Green sea turtles are one of the largest and most common species of marine turtle Sea turtles have a unique life cycle that takes place on land as well as in the sea Green sea turtles must survive many dangers if they wish to complete their life cycle and have young of their own Sea Turtles Are Reptiles Green sea turtles are reptiles This means they are cold-blooded and must use the sun to warm themselves Like other reptiles sea turtles lay eggs Sea turtles and most other reptiles do not care for their young after they hatch Life on Their Own Hundreds and thousands of sea turtles hatch from their eggs at the same time However from the moment a green sea turtle hatches it is on its own Female sea turtles do not care for their young Most of the young turtles will not survive long enough to complete their life cycle Green sea turtle hatchlings have to survive without the care of their mother
6 6 Size 4 9 feet 1 5 m long Weight more than 440 pounds 200 kg Color mostly brown with some green VITAL STATISTICS large scales called scutes smaller rear flippers to steer through the water and dig holes in the sand to lay eggs in large front flippers to pull the turtle through the water hard thick scaly skin to protect the turtle from predators and sharp coral reefs a hard protective shell that is smooth and streamlined so it does not drag through the water What Do Green Sea Turtles Look Like Over millions of years green sea turtles have adapted to life in the ocean They have a hard streamlined shell and large flippers to help them glide through the water Green Flesh Green sea turtles get their name because of the color of their flesh To look at green sea turtles are mostly brown
7 a gland behind the eyes for getting rid of any extra salt in the turtle’s body a stretchable neck for reaching into holes in reefs to look for food a strong sharp beak for biting off chunks of algae and seagrass Length Comparison Living Dinosaurs Sea turtles have been around since the time of the dinosaurs This means they have been swimming in the ocean for more than 100 million years Leatherback 115 inches 300 cm Loggerhead 80 inches 210 cm Green 60 inches 150 cm Hawksbill 40 inches 100 cm Flatback 35 inches 90 cm good eyesight when they are underwater but poor when out of the water nostrils for breathing when the turtle surfaces for air Kemp's ridley 25 inches 70 cm
