About the book: 2014 / The sea is the cradle of life on our planet. The first organisms arose in the sea - bacteria and single-celled creatures. Multicellular creatures of nature appeared in the sea - sponges, jellyfish, worms. More than 400 million years ago, it was from the sea that animals began their assault on land. We humans are land creatures, but our blood indicates a long-standing connection with the sea. It is as salty as sea water. Having got out onto land, our distant ancestors, then still almost fish, seemed to take with them part of their sea cradle. Is this why the seas and oceans, with their endless expanses sparkling in the sun and black cold abysses, attract so many people? A strange habitat that has long been alien to us. In some places there is almost a water desert, in others there is a riot of colors and life forms. Most of the inhabitants of the seas and oceans are not similar to land creatures. They move and breathe differently, they breed and communicate differently. This book tells about the habits and characteristics of sea animals. For middle and high school age.