These are like red anchor worms. They started at a sore on the fish's dorsal fin. I thought it was just a ragged fin with a bacterial infection. When I returned home from this weekend, it was apparent that this is some sort of parasite. I added some copper but a friend brought me a huge toadfish looking thing that does not have scales (smooth skinned).
Was the copper a mistake or is it ok with the new fish? Also, what is a good treatment for this? The other fish are clear for now...

Was the copper a mistake or is it ok with the new fish? Also, what is a good treatment for this? The other fish are clear for now...
