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
Evolution of cetaceans forms. As for dorudontines, there are some species within the family that do not have elongated vertebral bodies, which might be the immediate ancestors of Odontoceti and Mysticeti. The other basilosaurids became extinct. All modern baleen whales or mysticetes are filter-feeders which have baleen in place of teeth, though the exact means by which baleen is used differs among species (gulp-feeding within balaenopterids, skim-feeding within balaenids, and bottom plowing within eschrichtiids). the first members of both groups appeared during the middle Miocene. Filter feeding is very beneficial as it allows baleen whales to efficiently gain huge energy resources, which makes