Are They Wild ?

I was asked awhile back by a Thames Valley member if I could write something about distinguishing wild trout from stocked trout. I said sure but then life got in the way. I hope that many of you can relate. I thought about it some more afterwards and it dawned on me that there are quite a few factors  that go into determining whether or not a trout from one of our local Connecticut streams is wild or not.

Rather than get bogged down in graphs , statics, and all the other stuff that you might have to factor in, I thought I would just hit the highlights and speak of generalities.

For the most part when you look at a wild trout vs stocked trout, you will see striking physical differences. However, they may be deceiving if you have a river system like the Farmington River which has stocked, multi-year holdover, and truly wild trout all mixed in.  That being said, there are some common physical features that stand out with wild trout that you won’t see in other trout- even holdovers ( at least in this state). 

Here’s how I break it down. First, and probably the most important feature, is to look closely at the fins of the fish. All wild trout will have big beautiful and flawless fins. Stocked trout will have thick and stubby fins, worn out fins and sometimes one of the fins will actually be clipped . That trout is a wild brown from a club that I belong to. It is darkly colored, has colorful spots, but if you look at its right pectoral fin, it has a cut in it, not clipped. Sometimes , a wild fish will have  temporary scarring or damage to a fin if it had been digging out a red or trying to stuff itself under structure repeatedly during the day to hide. However for the most part, if you see that a trout  from a stream has flawless fins, I personally would lean towards it being a wild trout.

   A second feature that I would look at is the adipose fin. Many stocked trout have this fin clipped off. Almost all of the wild trout that I have seen in this state have a colored adipose fin that is either red or orangish. Again, however, a multi-year holdover may have a darkened adipose fin but not necessarily a vibrant colorful one. This brown was caught in a Class 1 WTMA.

Next I would look for colorful spots on its side with or without halos around them as well as halos around their brown spots. Most wild trout from this state will have either orange or red spots. But, you can’t go by that distinction alone. If you look up to the top of this blog, you will see the trout has colorful spots with halos, and what you can’t see is that it does have a colorful adipose. Plus, it is smaller in size that we stock at our club so it is a wild brown.

A Perfect Specimen

Another common physical feature that you see is a blue dot around the gill plate and/or a blue hue. I have never seen a stocked trout with these particular features. I do know that various strains throughout the United States and around the world differ in appearances but in terms this state, you can probably assume that it is wild when you see these.

Also, wild trout will have darker colors and look more vibrant than stocked fish. Stockies will most likely have a  ” washed out ” look. My fishing club uses a hatchery from Pennsylvania that delivers very beautiful looking trout but they still have a dullish appearance compared to the streams wild inhabitants.

Back to fins for a moment…wild trout will also have huge caudal fins ( tails ). If you look at the trout above, it has a very large caudal fin.

 Another feature that I look for are parr markings. Most likely if you see a young-of-year fish with parr marks on them in a trout stream, it is most likely wild. This alone can be deceiving though since our state can stock supplemental fingerlings and/or small stockies. I have caught stocked rainbows with their parr marks still on them. The brookie you see above is from a  ” blue line ” in Pennsylvania and is certainly wild.

Back to the fins again….a wild trout will have nice translucent fins. As you can see this wild brown has a very translucent anal fin. It’s pelvic is less visible but also very translucent. A stocked trout would not have this feature. This particular brown was caught on a Class 1 WTMA.

Finally, I would look at the size of the trout. For instance, my club does not stock any trout below 12 inches so when I catch a small brown, brookie, or rainbow below that size , then I can assume that it is wild. When I take in the account all of the other feature(s), then I can certainly deduce whether or not a trout is wild.

Connecticut has a vast amount of water that supports wild brown trout….and brook trout to a lesser degree. Based off of this map, you can be in any part of this state and have the potential to catch a wild trout. If you find yourself with a trout that looks wild to you and it has some or all of the distinguishing features  that I mentioned then chances are that it .


 My buddy  Joe always  says:  ” You can  delete  always and never  from your vocabulary. ” This  is true in many ways. Any Ichthyologist could probably  find some  fault in the  methods I described but, if you research the fishing data of your local waters and then apply some of it to your own fishing,  I think you will start to find it easier to identify a wild trout if you key in on some of the common physical features of wild trout in our state.

As always, be a good steward of your local environment and become  active with your local TU chapter  or conservation  group. As the newly elected  Membership  Chair for  Thames Valley TU ( chapter 282 ), we will always welcome more members ! Hope to see you out there some day.  And, get fishing ! You only have one life, you might as well enjoy a little of it !

One comment

  1. That is a good and educational read. When it comes to browns especially, it is hard for me to tell the difference between wild and stocked unless I know a specific area has been recently stocked with browns.

    I caught a brown in the fall several years ago that was as silvery as could be with muted spots. Caught out of a stream that warms up plenty in the summer but gets stocked in the fall, it was only about 8 inches or so. Hard to believe the Mass DFW would stock a trout of that size, but maybe they did. It was so unusually colored and silver I have always believed it was wild born one that made its way into the main river from a feeder brook, but who knows?


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