We're in Port Aransas, at the beach, and having an AWESOME time! During our latest little beach excursion, my brother came over to me, saying he'd found a cool shell. He'd been in water about 2' deep, and it wasn't a shell. It was a live sand dollar, about 2" wide. It's olive green on top, with a pattern a bit like a turtle shell, and the underside is a beautiful maroon. I was wondering if I could keep this in my aquarium. I know it would stay under the sand a lot, but I think it would be useful. As far as I know, they are algae and detritus eaters, and can't climb. Any imput? It's currently in a small tank, with a sponge filter and a couple of cool little snails.