young salmon before they go out to sea.
No interactions present.
The number of fingerprints on the flanks, 12 or 13, is more in line with Salmon, I think, as is the 3 spots on the opercle. They are very similar, though, indeed.
Edit: I do think some of the features are ambiguous, but I shall remove my agreement with Salmon, as there is too much doubt.
My Flickr photos...
You might be right. This is not very scientific, but as an angler I would call this a trout, because by May I would expect such a large parr to be smoulting.
It would have been nice to have a closeup of the head.
There is quite a nice comparison here: http://www.atlanticsalmontrust.org/knowledge/salmon-and-sea-trout-recogn...
But i agree this is a close one, i would lean towards the Trout due to the oranged adipose fin and the extent of the Maxilla which looks like (if its mouth were closed!) it would extend beyond the eye.
As an additional thought someone could just stick up the genus so we can all agree to that?
The pics of the juvenile fish in your link are brilliant. They show the differences.
One thing is consistent with what I was trying to say below re the usefulness of the presence of black and white piping on most of the fins of the S. trutta. This is a very good guide and will generally result in a reliable ID.
Your link and its diagrams are the best thing that could have been offered here,
Thanks for sharing.
Ive edited a long winded post on these species because of the quality of the diagrams in BDeeds link posted above for differentiating young trout and salmon.
One of the first things I look for personally is for the presence of striking black and white 'piping' on the fins, the presence of which indicates the species to be salmo trutta. Its very clear on the diagrams in the link and also on the image of the young brown trout above.
To the unfamiliar eye, the differences in the 2 species only become obvious when you have an example of each sitting beside each other.
Thats a beautiful wee trout above, stunning parr markings still there- ie the blue thumb prints along the flank, these are present on juveniles of both species.
Lat/Lng: 50.8397, -4.2262
OS grid ref: SS433068