Sand Dollars

Sand dollar / Clypeaster sp. / Family Clypeasteridae

Sand dollars are a type of sea urchin specially adapted to burrowing in sand. In contrast to most other sea urchins, the bodies of sand dollars are clothed in very small spines, which are used in locomotion, and to keep sediment off the body surface. The typical sand dollar has a greatly flattened body, and is usually circular.

Habitat

As the name suggests - and as may be seen in the image on this page - sand dollars burrow in sand. They move and burrow using tubed feet called podia.

Feeding

Sand dollars feed on particles picked up by the podia from the seabed. Particles are passed from podium to podium to special food grooves on the underside of their bodies, and through these to the mouth. Food includes not only particles that pass between the spines, but also diatoms and algal fragments collected by the tube feet, and small crustaceans.

Threats

Like most marine creatures, sand dollars may be affected by changes in sea temperature or water quality.