There are currently 62 known species of dolphins in the world. The Qujiang Marine Polar Park has the Bottlenose dolphins (Tursiops truncatus) introduced from Japan. During fixed periods of time every day, you can see wonderful dolphin show here. Dolphins are carnivores. They have more than 100 teeth, but each tooth is very small, so they only eat small fish and shrimp, squid. In the park, we feed the dolphins Russian herring, spring fish and squid. Dolphins belong to the family Class Delphinidae and are 2 to 3 meters long. Dolphins inhabit in the sea, but they are not fish, but like us, are mammals that breathe by their lungs. It has a breathing hole on the top of its head and rises to the surface of the water to take a breath after swimming a certain distance. They can swim very fast, up to 40 nautical miles per hour, equivalent to more than 20 meters per second. Tens of millions of years ago, the ancestors of dolphins lived on land like us and evolved three types of fins, called pectoral, dorsal and caudal fins. The pectoral fin is used to change the direction of swimming, the dorsal fin holds the balance, and the caudal fin provides the motivation to advance by beating the water.