Mutant trout

[knot trying]

I caught a very strange rainbow today. It was small (5"-6") and had a very strange body. The body did not taper smoothly to the tail, rather it seemed to end prematurely and then there was the tail fin. I guess you could call it "stumpy" but it was the strangest looking bow I've ever caught.

Is this a known mutation?

I also caught a stocker sized bow (7") that had shorter gill covers such that I could actually see the gills. I've caught a couple of other bows with this same "condition". Is this due to disease or is it also a mutation?

Just curious.



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What a long strange trip it's been...

[Bill Couch]

The shortened tail condition you describe is not uncommon. We think it occurs when fish are hatched in water low dissolved oxygen concentrations. The lack of oxygen retards development. When we see these fish, they are culled. However, often they are difficult to capture and stocked with the rest of the fish.

Similarily, the shortened gill cover (opercle) is an environmental problem. We believe it occurs when small trout or fry fall into water backwards, and the opercle is bent back sharply. It is similar to bending a fingernail back on itself, except the bent back portion of the opercle is living tissue, which dies, and leaves the gill exposed.

Neither condition is a genetic mutation.

Bill