Fun Facts About Sand Dollars

Sand dollars, dried.
Sand dollars, dried.

I love sand dollars. I have been lucky enough to find several washed up on the shore of Sanibel and Captiva over the years, nearly white from being faded by the sun. I’ve also found lots and lots of LIVE ones, which are ILLEGAL to keep in Lee County, Florida. Do you know how to tell the difference?

First, here are some fun facts about these beautiful and mystic animals:

  • Sand dollars are members of the Phylum Echinodermata family (in Greek that means “spiny skin.”
  • When a sand dollar dies and its spines fall off, its skeletal remains (the sand dollar you find on shore) is called a “test.”
  • Sand dollars move along the bottom of the sea by using their spines (tiny hairs called CILIA). Unlike their other relative, the star fish, that moves by using the tubes on its feet.
  • Over 600 sand dollars can live in one square yard.
  • The life span of a sand dollar is six to 10 years.
  • Sand dollars have a mouth with five “teeth” that can pulverize/chew tiny plants and animals.
  • The mouth of a sand dollar is called an “Aristotle’s lantern.” (If you’ve ever shaken a dried sand dollar and heard things rattling inside, it’s the five teeth – also known as the five doves in the Legend of the Sand Dollar!)
  • In calm water, sand dollars stand up. They lie flat in rough waters. (How cool would it be to see an entire ‘army’ of sand dollars standing on end, only partially buried?)
Sand dollar found on the shore.
Sand dollar found on the shore.

Is the sand dollar alive or dead?

MOVEMENT: Place the sand dollar in your palm. Look at its spines (the little hairs that cover the animal, called CILIA). If they’re moving, it’s alive.

YELLOW STAIN: Hold the sand dollar in your hand for a minute, if it stains your skin yellow, it’s alive. (That substance is called echinochrome. It is harmless to humans.)

HAIRY OR SMOOTH? Dead sand dollars are smooth and free of their spines/hairs. If it’s hairy, let it bury – place it in the water.

COLOR: Sand dollars fade to gray or white when they die.  When alive, they can be dark brown to purplish-reddish.

Live sand dollar in the water. See its hairy edges?
Live sand dollar in the water. See its hairy edges?

I have the best luck finding sand dollars early in the morning – the early bird definitely gets the washed-ashore sand dollar. Also, try the out-islands, like Cayo Costa. Happy hunting!

 

 

 

 

Author: GoToShell

Hi. I’m a Florida girl who loves seashells and shelling, and all kinds of beach bling. Sea glass is becoming a new obsession.