These little fellows are between a nickel and quarter in size and inhabit the sugar white sands of the Florida panhandle and Alabama beaches (at least). They don't seem to live in the water, but in the dry sand above the tide line, although they may be under water too and I just don't know. They are hard to see against the sand and are quick to scurry back into their little sand tunnels, but the kids love to catch them, put them in a bucket, name them, and then let them go. This one was Nicki or Nicole or something like that. I don't know what they really are, but we call them sand crabs, and they are decapods, so I suppose they are members of some crab family.