There's a local lake I've been fishing where I've been catching a fair number of channels that have slightly redish colored bumps, about the size of an eraser head, on/under their skin. Does anyone know what this might be? It's mainly larger fish (approx. 3lbs and up), but not always. I'd say about 1 out of every 5 fish I catch have this problem. If I catch another I'll try to take a picture before throwing it back. I don't dare eat them. The lake is not known for pollution so I'm thinking maybe some kind of parasite?