Baleen Whales Baleen Whales Baleen whales have plates of baleen. The name refers to the series of baleen plates in gums along each side of the whale's upper jaw.
Baleen plates are somewhat triangular and arranged like teeth in a comb.
The inner edge is frayed, and the fringes form a dense mat inside the mouth. Baleen is made mostly of keratin, a substance found in our fingernails and hair. The largest eat the smallest. Depending on the species, baleen whales also eat small schooling fishes, and a variety of crustaceans such as krill, copepods, and amphipods. Baleen plates work like a strainer.