[G 01 / Baleen] whales are named after the [G 18 / keratin] plates attached to the roof of their mouths. When the whale takes in a large mouthful of water, small crustaceans ([G 19 / krill]) and plankton are strained through a series of parallel slats with fringes that mat together to form a sieve. The whale uses its tongue to help swallow these creatures and the water passes out of its mouth at the sides.
The blue whale belongs to a group of six baleen whales called the '[G 27 / rorquals].' The word comes from the old Norse word 'rorhval,' meaning 'grooved whale.' These whales have large pleats in their throats that enables their throats to expand so that they can take in a tremendous volume of water in one gulp.
