Top two answers are good, just to add that if you prevent the gills from working properly the fish will also drown. If a fish is pulled backwards in the water it will drown
Top two answers are good, just to add that if you prevent the gills from working properly the fish will also drown. If a fish is pulled backwards in the water it will drown
The fish you have aren't known for fin nipping. Could be fin rot, which basically rots away fish fins. Take a close look at the others for signs of this.
The bag isn't really a good idea, that will just stress it out more.
Another possibility is that the fish has caught it's self on sharp...