White Flame Scallops are a variant of the red flame scallops, Lima scabra, from Florida and the Caribbean. These are less common then the red scallops, but are found in pretty much the same places but with a slightly different distribution. For some unknown reason we find a lot of these on our live rock farm, so most of the ones we sell come from there.
In an aquarium scallops will seek out a dark place, usually in a corner or under a rock and attach themselves there with basal threads that they secrete. They are filter feeders and will need to be fed fine particle foods like those used for corals and gorgonia. The tentacles are not poisonous and the scallops will not hurt any other inhabitants unless they swim into the scallop and it closes on them. If disturbed or threatened by another critter, they can detach themselves from whatever they are holding onto and actually swim through the tank. As the picture shows, they have a red interior like the red flame scallops, but the tentacles are all white instead of all red. I believe that they are actually a different subspecies, but I havent found anyone who lists them as such, so Ill go with the information I have.