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Unusual mouth shape on that fish, not from an isolated population is it?
Yes this small trout has an 'overshot' mouth. Undershots are more common, sometimes refered to as pug-nose- found in many fish species as you will know.
The lake in question is an isolated springfed water in an elevated position- a very small stream leaves it which is subterranean in places. It probably had indigenous trout at one time but it has been subject to many stockings of trout fry for decades.
In this case I think it is just an odd one.
OK cool, just hoped it might be an interesting ecotype from an isolated population evolving towards benthic feeding. Reminded me of some of the Salmonids from further East like S. obtusirostris or Lenok (Brachymystax)
I must look those up, I'm not familair with them. An example of an undershot mouth is here:
Have pics of the same thing in cod and pollack and I think its quite common in pike also.
Yeah, you see pictures of pugnose pike quite often, obviously doesn't affect their feeding as there are 20lb+ fish that get reported. In other fish it's suggested that fluctuating dissolved oxygen at critical development periods while still in the egg might cause this. Or could be just some crap genes involved..
Lat/Lng: 55.005, -6.014
OS grid ref: NW434751