The blue whale is a baleen whale, which means it has no teeth but instead has fringed baleen, or whalebone, plates in its mouth. These plates act as a food strainer. Plankton is trapped behind these plates when water is expelled from the whale's mouth. Although whales live in the sea, they are warm-blooded mammals like humans and other land mammals. A baby whale nurses on its mothers milk just like other baby mammals do.
Plankton are very small, microscopic plants and animals.
They have little or no power of locomotion and float in surface waters. They are found in fresh and salt water. Planktonic animals include protozoans. At one time protozoans were thought to be the first animals on earth. The name protozoan comes from the Greek word protos, which means first, and zoion, which means animal.