This ultra closeup of a Lettuce Coral shows the detail of the ridges and grooves on this stony coral. The Lettuce Coral is called a stony coral because these animals build a hard skeleton out of calcium carbonate using minerals the animals get from the ocean water. The surface of this skeleton contains many rough ridges, and the coral animals live in the crevices between these ridges.

Individual coral animals are called polyps (say, "PAH-lips"). There are about 60 polyps living on the surface of the coral in this picture.

The Lettuce Coral in this picture is about 2 inches wide. Notice that the ridges have many tiny grooves. The polyps have tiny tentacles that they use to catch food. During the day, the tentacles hide in the tiny grooves on the sides of the ridges for protection. At night, the polyps extend their tentacles into the water to feed on plankton and other creatures in the water. This picture shows the tips of these tentacles as bright yellow dots near the grooves on thee ridges.

Click here to see an entire Lettuce Coral colony on a reef near Bimini.