It is actually their nostrils

Cetaceans or whales are mammals and can be found along most coastlines around the world at certain times of year. Being mammals they do not to breath from time to time in order to stay alive, just a small detail. however, a lot of people are unaware that the blow holes that they breath from are actually their nostrils. This is highlighted in baleen whales, such as, blue whales, fin whales, minke whales and of course my beloved humpback whales (pictured below).

If you are able to encounter these animals from a certain perspective you will notice there are two distinct individual blowholes that they exhale and inhale from. Whereas, the toothed-whales have only one blowhole/nostril that they breath out of, which is due to their physical adaptation where they developed a hunting sensor known as eco-location. This large muscle that they have developed internally around one blowhole became so large that it actually blocked the other nostril, which they lost over time.

However, the larger baleen whale species still have their two blowholes, which is tucked away behind a splash guard that assists in them breathing without breathing in any sea water in rougher oceanic conditions.

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