Sand Dollars In The Delaware Inland Bays
a few years ago we abruptly went clamming one afternoon, because the boat decided to beach itself on a sand bar, not too far from the last buoy cluster for the Indian River Inlet and Indian River Bay. The best part was it was beached but the sand bar was really a ring of sand with a deeper depression in the center,. The water was dropping fast on the outgoing tide. We started pushing hard and fast.
While we are pushing this boat in several directions, trying to find a way out of the ring of sand. We kept finding clams, and several of these huge sand dollars. I have seen a lot of the smaller to tiny “tests” (skeletons/shell) on the beaches, but none this big, much less alive, in Delaware. It was also at this point we realized everyone was pushing the boat in a circle, because of the current. We decided to get a little more coordinated and push in the same direction. I was looking for sand dollars a the point and not even paying attention to the boat.
I found six more of these big sand dollars, took a few pictures and left them on the sand bar in the ring of forgotten boating skills. Sand dollars move across the sand and mud sifting and moving the substrate over their skin. Cilia move the sand across their skin as they move over, or through the substrate. Sand dollars feed on copepods, crustacean larvae, algae and detritus. Basically they eat all of the food like matter in the sand, dead or alive. when they move across the sand it looks like they are floating. I used to keep these in some of my coral reef tanks to clean the sand beds systems.
We found hundreds of sand dollar tests or shells, the test is what they leave behind when they die. The dredging that was done to replenish Dewey beach a few years ago pumped a lot of them onto shore. There aren’t any in the surf I have ever seen or found, which is one place you would think to find them but we don’t have the food supply in the sand that we used to have. The food supply in the inland bays is plentiful, because that was a lot of big sand dollars. That sand is loaded with critters and the water is full of algae and bacteria, good eats for any filter feeding invertebrate.