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 whale because of the lack of a melon and vocal cords. In a 2007 study, it was discovered that the larynx had U-shaped folds which are thought to be similar to vocal cords. They are positioned parallel to air flow, as opposed to the perpendicular vocal cords of terrestrial mammals. These may control air flow and cause vibrations. The walls of the larynx are able to contract which may generate sound with support from the arytenoid cartilages. The muscles surrounding the larynx may expel air rapidly or maintain a constant volume while diving. The eyes of baleen whales are relatively small