Ummm i would think that you could keep a low light clam if your params are good. Maybe a gigas, deresa, or a squamosa. Crocea and maxima would be a no cuz those need intense lighting. If you do get one, i might try to find it a nice spot on the rocks, closer to the light. He will either secrete an acid with melts the rock to his shape or drill himself into the rock. Good luck!