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 Great White Sharks Great white sharks are one of the largest predators on Earth The life cycle of a great white shark is different to many other species of shark Although they can grow very large great white sharks must overcome many challenges to complete their life cycles Sharks Are Fish Great white sharks are the largest predatory fish in the world Like other fish they use their gills to breathe underwater Water passes through a great white shark’s gills as it swims The gills take oxygen from the water If the shark stops swimming it will not get oxygen and it will drown Lone Hunters Great white sharks will often hunt in the same area as other great white sharks but they do not hunt in groups Most of the time they try to stay away from each other Great white sharks will only gather together for a short time to feed on a large animal such as a whale that has died Great white sharks are aggressive hunters
6 large pectoral fins that act like the wings on an aeroplane to help the shark steer rough tough skin offers protection when prey fights back large powerful tail to push through the water large dorsal fin for balance as the shark cuts through the water good eyesight to find prey even in very low light streamlined body shape to slide through the water What Do Great White Sharks Look Like Over millions of years great white sharks have adapted to life in the ocean Their body has evolved into a streamlined shape that makes them very good swimmers and hunters gills take oxygen from the water Size more than 19 feet 6 m long Weight more than 2 2 tons 2,000 kg Color dark gray back and lighter underbelly VITAL STATISTICS Night Attacks Great white sharks have good eyesight which means they can attack seals at night
7 Length Comparison Blood in the Water Great white sharks can follow the scent of blood for many miles to find food Whale shark 39 feet 12 m Great white shark 19 feet 6 m Thresher shark 16 feet 5 m Wobbegong 10 feet 3 m Scuba diver 5 6 feet 1 7 m eyes can roll back during an attack for protection rows of sharp serrated teeth to cut and tear chunks of meat from their prey smaller bottom teeth to hold the prey top teeth for cutting small holes that detect tiny amounts of electricity created by other animals helping the shark to find sick and injured prey great sense of smell to find prey
