Rotifers are called wheel animals. These organisms are aquatic and are usually found in fresh water. They are small, multicellular forms with a ciliated_corona. They are pseudocoelomates and they are also cell_constant. They can attach to a substrate by using their adhesion_glands.

These organisms are known as wheel animals because they have a ciliated corona that looks like a wheel. They also have jaws (pl: trophi) located within a muscular structure called the mastax. Rotifers are most often fresh-water, free-swimming forms. Some use their foot for attachment to a substrate.