Sand Dollars

The Sand Dollar is a spiny, hard-skinned animal that is shaped like a coin. They live on the sandy sea floor, most sand dollars are found at depths of 30 to 40 feet (9-12 m) and sand dollars partly bury themselves under the sand, with an edge poking up out of the sand. Sand Dollars are echinoderms, and are related to sea urchins and sea stars. Sand Dollars have 5-part radial symmetry. These invertebrates have a hard skin made of calcium carbonate plates. The bottom surface contains the mouth, many black spines (which trap food), and the cilia (small hairs) that help direct food into the mouth. Sand Dollars have tiny tube feet that are used as gills. The holes on the top surface are where the eggs and sperm are released. Sand Dollars eat tiny particles of food that float in the water.

Sand Dollars
Sand dollars