Here is the scientific way to tell the difference between a queen and a fighting conch. The bumps across the middle are nubby on a fighting and sharp on a queen. And of course, the queens can eventually get huge. Occasionally my conchs will dig in maybe 1/8th of an inch to sleep.I think they are very good for helping keep the top of the sand clean of algae.
My queens only work the top of the sand and they are a valuable addition to the sand bed clean-up crew which includes nassarius snails, bristle worms, pods and probably some things I don't even know are there. If it's a dsb you don't really want "sifters" just "shifters" like nassarius who are usually buried in the top layer unless it's feeding time.
Infalable - ceriths will sometimes be on the sand bed but spend more time on the rockwork.