Digestive system of humpback whales Digestive system of humpback whales The digestive system of humpback whales ("Megaptera novaeangliae") is adapted to digest tiny crustaceans such as krill, plankton, and small fish (including herring and mackerel) which the whale filters from the ocean using its baleen, a sieve-like structure in the upper jaw. Humpback whales belong to the parvorder baleen whales, which are carnivorous, seasonal feeders. The baleen, a sieve-like structure in the upper jaw made of keratin, is used to filter plankton, among other food sources, from the water. Ventral grooves are expandable concave furrows that line a whale's throat and have the peculiarity of
Baleen baleen. These baleen bristles are arranged in plates across the upper jaw of the whale. As a material for various human uses, baleen is usually called whalebone. It is not to be confused (but often is) with whale bone or whale's bone meaning the actual bones of whales, used in carving, for cutlery handles and other uses for the bones of various large species. Like other bone materials, this often functioned as a substitute for ivory. Depending on the species, a baleen plate can be long, and weigh up to . Its hairy fringes are called baleen hair or whalebone-hair.