Dolphins are sea mammals. They are members of Delphinidae family. They have to breathe air or they will die. Dolphins can hold their breath for six minutes.
Dolphins have smooth skin. Only baby dolphins are born with a few bristly hairs on their snouts. Their hair soon fall out. They have big tail and the fin on the top of their backs keep the dolphin from rolling over. The female dolphins have a thick layer of fat under their skin to keep the warm when they dive very deep. The dolphin's front fins are called flippers. They use them to turn left and right. Dolphins grow from 2 to 3 meters long and weight up to 75 kilograms.
Dolphins hunt together in a group. A group of dolphins is called a pod. They eat fish, shrimps, and small squids. They live in salt water oceans. When dolphins fear or see a ship close by they go near and follow it from distance, dolphins can leap out of the water and do somersaults.Sometimes they invent their own tricks and stunts after watching other dolphins perform.
Dolphins are very friendly to people and have never harmed anyone. They are very playful animals.