Kingdom: Animalia
Class: Echinoidea
Order:
Clypeasteroidea
Family: Dendrasteidae
Genus: Dendraster
Species: excentricus
Common Name: Eccentric
Sand Dollar because of the “star” that’s off center on its surface.
Morphology: Disk-shaped
with a cone appearance when lying flat.
Light gray, brown, to dark purple; covered by fine tube feet; and the
mouth is on the lower surface.
Size: Up to 75 mm wide (when laying flat, it can be up to 6
mm high).
Range: Baja, California to Alaska.
Habitat: Low
intertidal zone or on sandy beaches.
Often just the tests (i.e. hard external covering) of dead sand dollars
are found laying on the shores of the Puget Sound, WA and are mistaken for live
ones.
Diet: When
lying flat or moving through the sand, it feeds on diatoms and detritus that
fall onto the surface of the sand dollar.
Contains specialized tube feet, spines, mucus secreting glands, and
pedicellariae that are involved in suspension feeding while standing vertical.
Predators: Sea
stars, crabs and fish.
Links:
http://www.oceanlight.com/lightbox.php?sp=Dendraster_excentricus
http://www.divebums.com/FishID/Pages/sand_dollar.html
http://www.tropicabelize.com/Crab%20Collection/Crabs%20Photos/Legend%20of%20the%20Sand%20Dollar.htm
Reference:
Jangoux, Michel and
John M. Lawrence. 1983. Echinoderm Studies. Rodderdam: A. A. Balkema.
This page prepared by Abbie Moyer, Spring 2004