Digestive system of humpback whales stretching like an accordion. They allow whales to open their mandible to 90 degrees to gulp water and prey. They expel saltwater through the baleen plates, leaving behind krill and plankton. The whale's tongue plays a vital role in filter feeding, as it is used to push the water out of its mouth while keeping the prey trapped in its baleen bristles. As humpback whales do not have teeth, their food is swallowed whole and travels down the esophagus into the preliminary stomach (known as the forestomach) to be ground. Baleen whales have a multi-chambered stomach, divided into three distinct
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