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Fish: Cutthroat Trout

Fish ID

Post By: WapitiStalker      Posted: 11/27/2018 2:44:35 PM     Points: 0    
So I was going through some old pictures from the past and came across one I took while fishing a high mountain lake for dinner on a backpacking trip... I never gave much thought to what they were but now can see quite a difference between the two.. I was thinking they only had cutthroats in it but now I realize maybe one of them is a cutbow? or some regular high alpine rainbow trout? I know they can have many color variations depending on body of water or environment they live in or whatever but would like to see what you all think these fish are.. the one on bottom/ the smaller one is a cutthroat? which one? Thanks in advance I know it'll help me identify fish better on future trips.
 Reply by: Smitty413      Posted: 11/27/2018 4:38:07 PM     Points: 108    
Very nice fish! I have found cutbows in quite a few high mountain lakes, and those definitely look like cutbows to me. The cutthroats I've caught in the past in alpine lakes have had more red on their head and body, and more yellow coloring on their sides. Either way, great catch.
 Reply by: brookieflyfisher      Posted: 11/27/2018 5:56:55 PM     Points: 6139    
Both of your fish are pure cutthroat trout. Smitty's fish is also a pure cutthroat. Do not rely on body coloration to identify trout. Body coloration varies widely depending on subspecies, time of year, forage, and water clarity. Instead, rely on fin coloration, spotting patterns, and fin shape/placement.

The only way to reliably tell cutbow trout from pure cutthroats is by the presence of white tips on the anal and pelvic fins. White tips = rainbow genetics. No white tips = pure genetics. There are also slight differences in spotting patterns and coloration, but these vary widely depending on the strain of rainbow and strain of cutthroat that are crossed.

The CPW rarely if ever stocks cutbows at high elevation. High elevation lakes are supposed to be refugia for our threatened and endangered cutthroat populations, stocking fish contaminated with rainbow trout genetics would be counterproductive in most cases.
 Reply by: SirGreg88      Posted: 11/27/2018 8:26:32 PM     Points: 74    
I think those are fish
 Reply by: team FMFO      Posted: 11/27/2018 8:39:05 PM     Points: 3319    
 Reply by: buffchip      Posted: 11/28/2018 7:39:09 AM     Points: 2810    
Wow! I feel like I just sat through a seminar.
Thanks brookieflyfisher
 Reply by: Smitty413      Posted: 11/28/2018 9:29:53 AM     Points: 108    
Thanks Brookieflyfisher! Excellent information. I did know about using fin coloration to identify cutthroat trout, but didn't know it was conclusive. Would you mind sharing your source? I've had trouble finding ways to definitively identify trout.

As far as cut-bows go in high lakes, I agree that it would be counter productive for the DOW to stock them in high lakes. As far as I know, they are not stocking them actively in the lakes I frequent. However, I have caught them before (white tipped fins and all) in several high lakes, including lower Pomeroy lake, lower Bushnell lake, and Northfork Reservoir.

Here's a link to the USFS site verifying cut-bows in Pomery:
[log in for link]
 Reply by: bigbear57      Posted: 11/28/2018 12:45:29 PM     Points: 876    
They look like Colorado river strain cutthroats. The lower one could have been a Bonneville strain cutthroat. I would think that the difference in color is do to the age -maturity of the fish. The lower one is marked like a juvenile.
 Reply by: brookieflyfisher      Posted: 11/29/2018 11:17:50 AM     Points: 6139    
Smitty, my info comes from ID Fish and Game's work in the South Fork of the Snake. Unfortunately I can't find the gray literature that establishes the "white tips" thing, but it is in the ID regs book.

In other places (like where I am in UT), people look at spotting patterns most native cutthroat subspecies don't have many (or any) spots on the head, whereas rainbows and cutbows do.

Golden trout/cutthroat hybrids also get the white tips (pictured, from the Frank Church Wilderness in Idaho) which makes sense, golden trout are sometimes categorized not as their own species but rather a subspecies of rainbow trout. If you're seeing white tips in high elevation it could also be golden genetics, which is awesome (well...not for the cutthroat but it is for the angler!).

I thought I remembered reading once upon a time that Pomeroy and Bushnell had been stocked with goldens decades ago... perhaps the USGS saw the white tips and assumed cutbow instead of cutgold? Or maybe they did genetic testing that wasn't specific enough to parse between aguabonita and mykiss genes? I'd be interested in learning more.
 Reply by: Smitty413      Posted: 11/29/2018 4:33:39 PM     Points: 108    
Brookie, very interesting! Thanks! I had never thought about the possibility of those lakes having goldens. I agree that it isn't very good for the native's, but I definitely like the idea over Rainbows or cut-bows. I would also be interested in learning more.