A Differential interference contrast (DIC) light micrograph of a Rotifer of the genus Monostyla. Also called wheel animals, rotifers are microscopic aquatic animals and common in freshwater environments. They are surprisingly complex on the inside: they have a brain, reproductive organs, a bladder and a digestive system. They are omnivorous, eating bacteria, debris or small protozoans. Magnification: x575 when printed at 10 centimetres wide at its longest edge.