To better exploit rich marine food resources, they adapted by retaining certain useful traits through a gradual natural selection process. Their hind feet shrank, eventually disappearing and tails grew into flukes for swimming. The snout extended, raising the nostrils on top of the head to make breathing at the surface easier. These modifications eventually led to specialized whale adaptations such as powerful flukes and streamlined bodies for swimming and blowholes for easier surface breathing. Humpbacks, like blue and gray whales, are baleen whales.
Baleen whales are filter feeders.
Baleen are plates of fingernail-like material that look like toothbrush bristles hanging from the top of the mouth. Baleen whales have no teeth. As it opens its mouth to take in water and food, throat grooves under the jaw expand allowing in more prey. The mouth is closed and the water is strained or filtered out through the baleen with a push of the tongue. The food is trapped inside and swallowed whole.