Rotifers: Rotifera - Physical Characteristics

Rotifers (ROH-tuh-fuhrs) are microscopic animals that have complex jaws and a wheel organ, which is used for movement and feeding. Most rotifers are 0.006 to 0.02 inch (150 to 500 micrometers) long. The body usually is divided into a head, a trunk, and a foot. The largest organ in the head is the wheel organ, which is made up of beating hairlike fibers arranged in bands around the mouth. The jaw has a single sharp tooth or a plate with several strong teeth used to grab and pierce food. The trunk shape varies from long to spherical or baglike. The foot has one or several sections, and it often has two toes with sticky glands at the tips.