Norm,
I've been marking fish for five years now and have learned the following...
Clipping the caudal fin or tail is the easiest. The fin should be clipped with a surgically sharp scissors that have been cleaned with rubbing alcohol (to lessen liklihood for fungal growth), and ideally recleaned after each use.
When I'm marking HSB for future identification I clip the upper point one year, then the lower point the next year, followed by an unclipped class. When clipping the point of the tail, don't remove the entire point, just the last half of it, at a 45 degree angle to the body. You could also clip the third year class by removing the top one-half of the most anterior dorsal spine.
When clipping a fish's caudal fin you will find that the fish has no difficulty swimming, but may experience a week or two that it loses a little straight-line speed while the fin regrows. I have not noted any problems with body condition of these fish after subsequent recapture. I really don't believe that it causes them any harm. The fin regrows quickly. The reason that you will be able to identify this fish's year class is that the soft rays of the caudal fin will have a slight wave or curve to them after healing. Sometimes the fin will not regrow to a sharp point, but with a slight bluntness. The casual observer will not notice this but you will learn to effectively identify these fish by year class.
I think that tagging fish with a numbered tag is cumbersome, time-consuming and esthetically unpleasing, and probably with considerably higher injury rate to the "tagee". In my personal opinion this is a tool best used for research purposes by trained biologist.
What species of fish are you considering these markings, and to what end?
Bruce
