There are a couple different snails called moon snails by hobbyists. One is Norissia, which is usually sold as a "red footed moon snail." It's from very cold water and is not suitable for tanks both because of the temperature where it's collected and because it feeds on kelp, which we don't have in the hobby. There's also the naticids, which are what most people outside of the hobby call moon snails. These guys are carnivorous and mostly prey on other mollusks. If you've ever been to the beach and seen shells with perfectly round holes drilled in them then you've seen the work of moon snails. These guys have no business being in a reef tank, but they can be interesting in a species tank.
