The colors on that clam are very cool!! However, the clam is gaping, it is stressed out, could be because it is directly on the sandbed, really hard to tell from the pic which one (T maxima or T crocea) it is, but it looks like a crocea to me, but either one are a boring type clam that digs into rock. The have strong byssal filiments that need to anchor to the rock to give it stability. I would either put it on a low rock, or bury a flat roch, just under the top of the sand, for it to attatch too.