Baleen Baleen Baleen is a filter-feeder system inside the mouths of baleen whales. The baleen system works by a whale opening its mouth underwater and taking in water. The whale then pushes the water out, and animals such as krill are filtered by the baleen and remain as food source for the whale. Baleen is similar to bristles and consists of keratin, the same substance found in human fingernails and hair. Baleen is a skin derivative. Some whales, such as the bowhead whale, have longer baleen than others. Other whales, such as the gray whale, only use one side of their
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