There are about 340 kinds of sharks living in the ocean. Whale shark is the largest, nearly 20 meters long. The smallest shark is about 15 cm long. Shark scales are shield-shaped, with large pectoral fins and developed caudal fins. Kouga is fierce, quick-moving, and his sharp teeth scare other fish, so he is also called the overlord of the sea.
Sharks have sensitive inner ears, and the lateral lines of their bodies can feel tiny vibrations, and they can feel the sound made by people swimming hundreds of meters away hitting people. It is also very sensitive to the extremely weak current in the water, and many fish will born to die as long as they pass by it.
Although sharks are fierce, most of them will not attack humans. They live at the bottom of the ocean and feed on fish, shrimp and other creatures in the water.
There are about 20 kinds of sharks that can eat people, and they are particularly sensitive to the smell of blood. These sharks live in the upper and middle layers of the ocean and feed on marine animals and fish. The most ferocious is the great white shark, which is about 10 meter long. Hammerhead sharks also attack humans.