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 contain the Sei whale, Bryde's whale, Eden's whale, the blue whale, and Omura's whale. Cetotheriidae consists of only one living member: the pygmy right whale ("Caperea marginata"). The first descriptions date back to the 1840s of bones and baleen plates resembling a smaller version of the right whale, and was named "Balaena marginata". In 1864, it was moved into the genus "Caperea" after a skull of another specimen was discovered. Six years later, the pygmy right whale was classified under the family Neobalaenidae. Despite its name, the pygmy right whale is more genetically similar to rorquals and gray whales than