A whale's nose is called a blowhole, which is located on the top of its head.
The Blowhole: A Whale's Nostril
Unlike humans and most other mammals that have their nostrils at the end of their snout, whales have evolved to have their nostrils, now called blowholes, on the top of their heads. This adaptation allows them to breathe while swimming at the surface without needing to lift their entire head out of the water. The blowhole is a key feature in cetaceans, the group of marine mammals that includes whales, dolphins, and porpoises.
Evolution of the Blowhole
The blowhole is homologous with the nostril of other mammals, according to cetology, the study of whales and cetaceans. This means that they have a common ancestor and that the whale’s blowhole evolved through a gradual movement of the nostrils to the top of the head. This evolutionary shift was crucial for the adaptation of cetaceans to an aquatic life, allowing them to surface quickly, breathe, and submerge again with minimal effort.
Types of Blowholes
- Baleen Whales: These whales have two blowholes, a pair that is side by side at the top of their head.
- Toothed Whales: Most toothed whales, such as dolphins and porpoises, have one blowhole.
How the Blowhole Works
The blowhole is a muscular opening that allows whales to quickly expel used air and inhale fresh air. The muscles around the blowhole contract to seal the opening when the whale submerges, preventing water from entering its respiratory system.
Key Points
- The blowhole is located on the top of the whale’s head.
- It is the whale's breathing hole.
- It evolved from the nostrils of terrestrial mammals.
- Baleen whales have two blowholes, while toothed whales typically have one.
- The blowhole is a muscular opening that seals when underwater.
