First-time visitors Mary C. and Andy P. from Natick, MA, were kind enough to send along this photo of some “baby” sand dollars they found in the waters in front of Ocean’s Reach (before gently returning them back to the sea).
They were thrilled with their visit here and the opportunity to learn so much about our incredible sealife.
And sand dollars are indeed quite incredible. Did you know:
— In their sandy seafloor habitat, sand dollars use their fuzzy spines, aided by tiny hairs (cilia), to ferry food particles along their bodies to a central mouth on their bottom side. Sand dollars also breathe through their spines. They lose their spines soon after they die, so that’s why the sand dollars typically found on shore are smooth, hard and bleached white by the sun.
— In rough waters, sand dollars really don’t have a good way to prevent themselves from being tossed around. Adult sand dollars are heavy enough that they simply lie flat and cling to the ocean floor, but juvenile sand dollars learn to swallow grains of sand to give themselves added weight.
— A sand dollar is a notoriously slow eater. Their mouth has a jaw with five teeth-like sections to grind up food, which it may do for up to 15 minutes before they swallow. It can take the sand dollar up to two days to digest its food.
— Like counting the rings on a tree stump, scientists age a sand dollar specimen by simply counting the rings in the sand dollars’ exoskeleton. They don’t have to count high — sand dollars usually live six to 10 years.