After death, the color fades and the skeleton becomes very white. Sand Dollars are a very difficult animal to keep successfully in home aquaria. Clean: get sand dollar clean and mostly free from excess sand by soaking in fresh water for a few hours…change the water out a few times as it discolors. Sand Dollars, order Clypeasteroida, live in the benthic zone of soft and/or muddy sandbeds. If the hairs move, the sand dollar is alive. If a sand dollar is moist or solid in your hand, there's a good chance that it's alive or recently deceased, even if you found it washed up on the beach.
When they are alive, sand dollars secrete echinochrome, a harmless substance that will turn your skin yellow. Do you have a tank with a substrate like this that is rich in algal, larval, copepods, and diatoms? If the hairs don't move, feel free to take the sand dollar home. Check the color. After the animal dies, the sun causes its color to fade, and the skeleton eventually turns silvery-white. The term sand dollar (also known as a sea cookie or snapper biscuit in New Zealand, or pansy shell in South Africa) refers to species of flat, burrowing sea urchins belonging to the order Clypeasteroida.Some species within the order, not quite as flat, are known as sea biscuits.
Sand dollars can vary from a deep brown to a purplish-red color when alive. People thought the skeletal remains (called the test) resembled silver coin currency, which is how the name “sand dollar” came about.
The common name for these animals comes from their likeness to silver dollars. A sand dollar (Echinarachnius parma) is an echinoid, a type of invertebrate animal whose skeletons—called tests—are commonly found on beaches the world over.The test is usually white or grayish-white, with a star-shaped marking in its center. If it leaves a yellow spot behind, it is alive. Unfortunately my recommendation to you is to do your best to keep it alive. Place it gently back into the ocean. 2. Sand dollars are grey, brown or purplish when they are alive. (Related animals include other sea urchins, sea cucumbers, and starfish. Brush the hairs with your hand. Hold a sand dollar in your hand for a minute.