Sand Dollar: A Weight Belt for the Juvenile

See allHide authors and affiliations

Science  06 Jul 1973:
Vol. 181, Issue 4094, pp. 73-74
DOI: 10.1126/science.181.4094.73


Juvenile sand dollars (Dendraster excentricus) selectively ingest heavy sand grains from the substrate and store them in an intestinal diverticulum which may function as a weight belt, assisting the young animal to remain in the shifting sandy environment. The sand disappears from the diverticulum when the animal reaches the length of 30 millimeters.

Stay Connected to Science