Panther, nice looking clam and looks to be a good size too! A suggestion is to place him on a piece of flat rock that he can bury his byssal foot into and then bury this in the sand if you want to keep him on the sand. T. Crocea like to be on rock and will actually drill their byssal foot into rock.....If on a small piece of rock you can then move it to a different position in case he doesn't like the one where you have him. I have heard of them throwing themselves off various rock positions that they don't like. Now derasa and squamosa clams do like sand as opposed to rock....Also, as yours seems to be fairly large you may not need to be taking him out to feed him as you would if he was under 3" in size.......good luck, looks like a very very fine specimen.....