For sure. I know FIRSTHAND that sallys will catch and eat any fish that they can fit into their claws and isn't fast enough to get away. Usually the ones that live in and out of the rocks too -- like my firefish and sixline wrasse, RIP. Keep in mind, these guys are running a business. Some people are unscrupulous and will do anything for a sale, unfortunately. Sometimes, I think that they will sell you stuff that will die/kill on purpose, so that you have to come back to them to replace the dead animal.