Lamprey in SE MN Trout Streams

General trout, fishing, conservation, or anything outdoors related discussion. Trip reports and stream conditions welcome, but please do not name streams.
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brntrout
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Lamprey in SE MN Trout Streams

Post by brntrout »

Recently on popular stream South of I-90 I caught a nice size trout with a lamprey attached to it. I knew American Brook Lamprey were native to our area but they are not parasitic so I researched what other lamprey's are native to our area. What I found is Minnesota has five different species native to our state they are: American Brook lamprey, Chestnut Lamprey, Silver Lamprey, Northern Brook Lamprey and Southern Brook Lamprey. However, only two are parasites, they are the Chestnut Lamprey and Silver Lamprey. The Chestnut Lamprey is the one in our designated trout streams. Adult Chestnut Lamprey are about is 8 to 10 inches long, have teeth with two points and are olive/gray on top and yellow bottom. The Silver Lamprey is 9 to 14 inches long, have teeth with one point and are gray on top with silver bottom. How harmful are Chestnut Lamprey to trout I really do not know, but i do know i caught a few other trout the same day that had bite marks from Chestnut Lamprey's. It does appear trout have the ability to rid themselves of these parasites. If there is a mortality rate to trout from Chestnut Lamprey's I have no idea what it is?

For more Information check out this link: https://files.dnr.state.mn.us/education ... ochure.pdf

S.T.Fanatic
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Post by S.T.Fanatic »

After the 07 flood there were thousands of them in every stream around. Why, I have no idea.
“What more delightful avocation than to take a piece of land and by cautious experimentation to prove how it works. What more substantial service to conservation than to practice it on one's own land?” Aldo Leopold

S.T.Fanatic
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Re: Lamprey in SE MN Trout Streams

Post by S.T.Fanatic »

One from this spring N of 90.

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“What more delightful avocation than to take a piece of land and by cautious experimentation to prove how it works. What more substantial service to conservation than to practice it on one's own land?” Aldo Leopold

brntrout
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Post by brntrout »

The Chestnut Brook Lamprey is not as common as the American Brook Lamprey in our area which is not a parasite lamprey. As far as having thousands of them ( probably mainly American Brook Lamprey)after the 2007 flood, I suppose its a strong possibility the flood made habitat conditions more favorable for their survival. On the overall after a big flood especially in late summer stream conditions usually are much improved for successful natural reproduction of trout as well. That situation is just about always good for one spawning season only. So its possible the 07 flood increased lamprey natural reproduction capabilities too?

FlyFisherJoe
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Post by FlyFisherJoe »

Do you then detach the lamprey or leave it on?

brntrout
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Re:

Post by brntrout »

FlyFisherJoe wrote:Do you then detach the lamprey or leave it on?
The fish I caught the lamprey detached itself as soon as I landed the fish and handled it out of the water. Since Chestnut Lamprey's can be harmful to fish I would remove the lamprey if it doesn't let go when you land the fish.

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TaG
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Post by TaG »

Those creatures look nasty, I have an irrational fear of snakes. Lampreys look to much like a snake, I would probably not touch the thinking to get it off the trout.

High Stick
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Post by High Stick »

There was some fascinating video on Instagram this spring of an angler filming a brook lamprey mating frenzy in a stream south of 90.

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