Closed-Mouth Coral

A live coral polyp with turquoise tissue and brown tentacles closes its mouth (the slit at the center of the radiating ribs) tight. The coral uses its tentacles to catch food, which it then funnels into its mouth. After eating, waste leaves through the same opening. This photo, taken at 6x zoom, was an image of distinction in the 2009 Nikon Small World photomicrography competition