A whale’s blowhole is located on the top of their head. Whales have evolved from land-living mammals. As such, whales must breathe air regularly to survive, though they can remain submerged underwater for long periods of time.
Whale species such as the sperm whale are able to stay submerged underwater for as much as 90 minutes, though other whale species can only stay underwater for 20 minutes. They have blowholes (modified nostrils) located on top of their heads, through which air is taken in and expelled. They are warm-blooded, and have a layer of fat, or blubber, under the skin.