Species · GBIF taxon 2279084
Eccentric Sand Dollar
Dendraster excentricusAlso known as Western Sand Dollar, Pacific Sand Dollar, Sea-Cake, Biscuit-Urchin
Eccentric sand dollars are specialized flat sea urchins that live in dense colonies on sandy seafloors along the Pacific coast. Unlike other sand dollars, they frequently align themselves vertically, burying their front edge in the sand and letting the rest of their body stand upright in the water column to catch drifting plankton. Their dark purple, brown, or grey bodies are covered in a velvet-like coat of tiny spines and cilia that move food toward their central mouth.
MarineInvertebrateFilter Feeder
Licensed referenceD. Gordon E. Robertson / CC BY-SA 3.0 · cc-by-sa
- diet
- Plankton, diatoms, and organic detritus suspended in the water column
- family
- Dendrasteridae
- threats
- Coastal development, ocean acidification, pollution, and heavy foot traffic in intertidal zones
- life Span
- Up to 10 to 15 years
NE
Safe to observe at a normal distance.
- Look for live beds: In calm water, look for dark, fuzzy discs standing vertically on edge in the sand.
- Handle with care: Live individuals are covered in tiny, moving spines that stain hands yellow-green; return them gently to the water.
- Check beach finds: Only collect white, smooth, spineless tests, as these are already dead.