The sea covers 70 per cent of the world, but we know very little about it. Many different and wonderful animals live in the sea. Some of them are very small and some of them are very big. In fact, the biggest animal in the world lives in the sea. It’s the blue whale.
Blue whales can grow to be more than 27 metres long, and can weigh 150 tonnes. They have huge tails which they use to push themselves through the water. They can swim as fast as30 kilometres an hour. But blue whales are not fish. They cannot breathe underwater, but they can stay there for twenty-five minutes. Sometimes they swim more than 100 metres down below the surface. When they come up to breathe, they shoot water out of two holes in the top of their heads. Sometimes the water shoots 9 metres nto the air!
Blue whales can live for up to ninety years. They travel all over the world, usually n pairs or small groups. As they swim, they talk to each other by singing.their songs can be heard 1,200 kilometres away! In the summer they live in the sea near the North and South poles. In the winter they swim to warmer water. Their babes are born in the warmer water in the winter. When the babes are born, they are already 8 metres lon!But although these large animals are so big, not many people see them. There is a lot of sea to hide in!