I caught 3 channels today. Two were covered in some kind of pimples, almost looked like blisters, not much bigger than the end of a ball piont pen. I was told they were worms. Are they? They came out of a farm pond. If they are worms, can they ( the worms ) be killed? Is there something that can be put in the water to kill them. If not worms, what is wrong with the fish.