Pond Boss Forums INTRO Questions & Observations Fin clipping or marking

Is there a generally accepted method of marking fish? For example, the first year, are fish generally fin clipped one way, the second year, another, the third year, yet another etc.? Should the fin be clipped close to the body or further away? Does the fin grow back quickly so that we loose our markings?

Does clipping the fin of a fish impair its survivability? Is there a special way to clip a fin? If a pelvic or pectoral fin is clipped, does that affect the ability of the fish to swim straight? If a spinal fin is clipped, does that affect the ability of the fish to protect itself?

What about the use of tags? Is that something that we should reasonability consider?

Does the size of the fish affect how we mark it?
Any other information about this information would be greatly appreciated.

This information is scattered and incomplete on this forum. I would like to get it one place where we can all find it.

Hi Norm,

There is a koi in our ornamental pond that is missing the left front pectoral fin, has been missing it since it was a young fish, though there is the stump that moves as if a fin were attached. This fish thrives and swims normally. Also, there was another koi in a 55 gallon tank in the building where I work that regenerated the lower lobe of its tail fin which was bitten off by an aggressive fish. It, too, swam normally albeit with a slight limp, until the fin grew back. However, the more aggressive fish, after a year of bullying, finally finished it off.

Joe

Good question. I've been wondering the same thing. Numbered tags would seem to be a great little tool. Especially for those of us with fairly small ponds.

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

Pelvic fins can also be clipped, or bitten off (which is my proffesors technique). I think fins regenerate faster on small fish, and maynot on older fish.

Floy tags are another tagging option. But they are more intrusive. Numbered tags are also more expensive and for almost all applications totaly unneccesary.

I had pretty good luck using a paper punch and putting holes in the anal fins and pectoral fins. I did a "count-the-bass" survey one time where I
punched holes and released all bass. Holes were coded for length by the fin I picked. All punches were recorded. Also all recatches were recorded. At first, recatches were seldom, but by the end of the summer recatches were about 75-80% which gave me a rough estimate, based on the number punched, of the number of bass in my pond of 3.5 acres. The next year the scars were still evident but were hard to identify 2 years later.

Norm--About 3 or 4 years ago we tagged bass in our 2 acre pond with the T-anchor style tags and we still catch some fish with tags in them. I'm sure there is not 100% retention but there are still plenty with tags in them.Some have infected looking spots where the tag was inserted although their overall health seems fine.

I worked for a fisheries research station and one of the projects was how well certain types of clips and marks would show up over the years. Some were freeze branded and others received various clips. Results were extremely varied. Some fish had well defined clips 3 years later, some grew back but you could tell IF you looked very closely, and others showed no signs of being clipped. Those bass ranged from 12-18 inches. We would also have tagged bass in lakes that tagged when they were 6-8 inches and we recovered them at 16-18 inches still clipped. If you don't want to tag them I would clip the pelvic fins as close to the body as possible with scissors and if possible trim the fins up when they get recaptured later on. What kind of project are you working on? We tagged ours to look at individual growth. I'd highly recommend buying the numbered tags for doing this. I tried the cheaper route by numbering my own tags, but after a year or so algae covered the tag making it virtually impossible to rub off without rubbing off the numbers. I can still read one from time to time, but not most. Good luck.

Mike

It's amazing how adaptable fish can be that are missing fins. I have caught bluegills with their entire caudal fin missing probably from musky attacks in a local lake. Everything healed up nice but there was no tail!

Speaking of fins I have seen some interesting anomolies regarding fish fins as a taxidermist. I once took a crappie in which the pelvic fins were all one conjoined fin like a hand held fan. I also took a walleye in once that never grew one of it's pelvic fins. It wasn't cut off etc. it just never grew one and had scales where the fin should have been.

Thanks for the information everyone. In our particular lake, we have such heavy predation that there is almost no successful reproduction except for bluegills. That means I must be stocking fish constantly. The big question then becomes, how many and how often? Since some fish can live 10 years or more, I need a way to see this.

More than my personal need, as we are becoming better fish managers, more of us will want to start marking our fish. Rather than scattered information everywhere, I hope that this will become a reference thread.

Bruce, I don't know how long HSB or BG live, but how do you mark years 4-5-6 and so on? I would think that you will want to keep track of your fish through out their lives.

Mike, I've never heard of "freeze branding" before. Can you describe it?

Also, what method seemed to work best for long-term studies?

If you mark top of the tail, then bottom, then nothing, in theory you can tell a one from a four from a seven year-old fish by size alone. That is a good question, though. I guess I'll see if I'm right as the fish get older.

Norm,

For our method of freeze branding we had an insulated aluminum canister that would hold 1-2 gallons of liquid nitrogen. At the bottom of the canister, protruding from the side, was a large brass nipple. We would hold the fish firmly up to the brass for about 3 seconds. It would leave a fairly distinct mark. Sometimes we would do this after clipping the pelvic fins to slow or prevent regrowth. It was described to me as leaving a scar. It's cold enough to disfigure and permanently damage the skin cells. However, as a long term marking tool it didn't work well for us. It was the mark that was the least distinguishable after a couple of years. We didn't do any studies on tag retention, but I'd be something could be found online. From my experiences, in general, a good pelvic clip close to the body will give you atleast 2-3 good years. Hopefully you could catch and reclip the fish as they grow. You could clip one pelvic fin and leave the other as a reference if one does regrow. Sometimes one can notice subtle differences in the fins that have regrown.
FYI another marking technique I've seen for multiple groups of fish is removing one of the several dorsal spines. Depending on which spine or spines were removed indicated to us which group of fish we were dealing with.
I typed in "freeze branding fish" in google and found several articles on the subject if you want to learn more.

Mike

Freeze branding cattle causes the hair to fall out, at first, but kills the pigment cells. When the hair grow back , it grows back white. So the brand eventually consists of white hair.

As far as I know, fish, when freeze branded, never grow hair in that spot. ;-)
But evidently, from what I have read here, it doesn't remove the color from the scales either.