There are many similarities between whales and fish. For example, they all live in water and their living environment is similar; In addition, their physical characteristics are similar to those of fish, because their bodies are streamlined, which makes them better swimmers. Although they have so much in common with fish, they are not fish themselves, but mammals, just not mammals living on land.
As a mammal, whales have some key characteristics that are different from those of fish. For example, the way whales breathe is quite different from that of fish. Fish can live in the water, using gills to breathe is very convenient; Whales, on the other hand, use lungs to breathe, which prevents them from being submerged for long periods of time and requires them to come to the surface to breathe. In addition, the reproductive methods of fish and whales are also different, fish are generally oviparous, while whales, as a mammal, use the viviparous method of reproduction.
As mentioned above, whales are a kind of mammals, they breathe with lungs, so they need to come out of the water regularly to breathe. However, this does not mean that they can live on land. Most whales live in the sea, a small number live in fresh water, but no one lives on land. Although they can live out of water for a while, they can't live for too long. Being out of water for a while makes their skin dry, and being out of water for a long time may cause them to die.
