He would , he can either be healthier than the rest and not yet showing signs or a bit more prone than the rest. I dont quite trust pet stores testing my water but if it's all you have. Have you seen any ich,velvet, or any sort of disease on your fish. Maybe turn fins ,beat up elsewhere?water is fine I have brought it to two different stores for testing comes out fine. Some fish were before others were after. If water chemistry was the issue, wouldn't the melanarus get sick?
No given fish will kill parasites, their a temporary remedy is all. I am almost certain that it has to do with water chemistry. And that the fishes being chewed might've happened after the fact. Once a fish dies all inhabitants see that as a mealSo the other fishes tail fins are chewed up. don't see any ich. have 2 skunk cleaners and cleaner wrasse so I hope that's sufficient to keep parasites at bay but I'm new and ignorant.