ADAPTATION Echolocation - Mechanics
|Most cetaceans can see well in water but are myopic (short-sighted) in air.
However, they do not see well at water-depths where there is little to no light.
Odontoceti have overcome this disadvantage by using a process called echolocation.
Echolocation works like a radar, where sonar waves, sounding like clicks, are produced in the balloon-like nasal sacs by the melon. They pass through the head of the cetacean and travel through the water until they reach an object. The sonar waves are too slow to pass through the object and are bounced back, entering the telescopic-like oil filled lower jaw that acts as the receptor. This process helps the cetacean to navigate through the water and hunt for food. The squeaks, whistles, grunts and other noises produced from the larynx are used in communication.
Of the modern whales, only the Odontoceti use echolocation. Since Mysticeti do not hunt their prey or regularly dive to great depths, echolocation is not necessary.