Whales are mammals.

whales are viviparous mammals, not fish. It takes a year for a calf to grow up with breast milk. Fish are oviparous vertebrates. Parent fish generally have no habit of taking care of small fish. The whale's "fin" actually evolved from its limbs. Fish are not. Whales breathe with their lungs; Fish breathe through gills. The whale is warm-blooded animals; And fish are warm-blooded animals. You can't distinguish whales from fish by whether they have fish scales or not. Because many fish also have no scales.

Whale is the common name of cetaceans in marine mammals, which is divided into toothed whales and baleen whales. Under cetaceans, the dolphin family is included.

whales live in the ocean. There is a very thick layer of fat under the whale's skin, that is, whale oil, which can keep the whale warm and store energy for emergencies. Because the whale has many special structures in its body, it can hold its breath and slow down its heartbeat for a long time, so when it sinks to the bottom of the sea, it will take a long time to surface again. In addition to the structure of storing oxygen, when a certain part of the body needs a large amount of blood supply, the body will have a special function of centralized supply.