Sand Dollar

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Project Description

Sand Dollar

Mellita quinquiesperforata

Range/Geographic Distribution: From Virginia to Brazil. 

Habitat: Shallow, sandy waters along beaches and bays. 

Description: A round, flat echinoderm with five oval holes called lunules.  The body of live sand dollars is gray/green and covered in tiny spines and tube feet.  After death, sand dollar tests (shells) lose the spines and tube feet and are white in color. 

Size: Can reach three inches in diameter. 

Food: Detritus, microorganisms, algae, and crustaceans.

Breeding:  Breed in the spring and summer.  Reproduce by sexual, external fertilization and the fertilized eggs hatch into planktonic larvae.  After about six weeks, the larvae metamorphosize into juveniles and settle onto the substrate.  

Predators: Sea stars, crabs, flounder, haddock, cod, and other bottom feeding fish.

Conservation Status:  Tybee’s city ordinance prohibits removing live sand dollars from the beach. 

Interesting Fact: Sand dollars, also called key-hole urchins, can live for ten years.  These echinoderms can only right themselves after being turned over by burying vertically into the sand.  The holes, or lunules, in a sand dollar’s body help to keep it from being swept away by waves.

On the Coast:  Live sand dollars are sometimes seen along the surf but should never be collected.  The bleached-white tests of dead sand dollars often wash up onto Georgia’s beaches and are a favorite for beachcombers.

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