Sand Dollar (Dendraster excentricus)
|More Ocean Resources
If you enjoy walking along the beach at low tide, you have probably seen a sand dollar along the water's edge.
The lucky explorer is commonly rewarded by seeing a live sand dollar with the purple spines on the back.
Live sand dollars appear much different than the usual bone white, five point circular shells that show up along the boardwalk or sidewalk.
Sand dollars are invertebrates, are echinoderms, relatives to sea stars, characterized by a spiny circular shell. The top picture shows a sand dollar with purple and brown shaded spines.
The five point star is the field identification mark for the back of the shell. The picture shows the front of the shell.
As the name suggests, sand dollars live in on the top layer of sand (or just below it) in an area up to one-half mile beyond the lowest of low tide marks. Since they are marine animals, they die if left exposed to sun and air for a period of time.
Their ability to move helps them relocate according to the movement of the tides. They spend their day eating organic material floating on the water or on the top level of sand.
Sand dollars are found throughout the world.
Source: 2006 Patricia A. Michaels