Are Whales Fish?

Like mammals on the land, whales are viviparous animals. That is to say, a female whale gives birth to a baby whale, and the baby whale grows up by the feeding on its mother's breast. However, most fishes are oviparous. The breathing method of whales is different from that of fishes. Generally speaking, fishes breathe with the gills, while whales breathe with lungs. A whale will float onto the surface of water to take a breath after a certain period of time.

Long, long ago, whales lived on the land; later, they lived in water, and their bodies became streamlined like fish.