narmour wrote:If you are referring to the photo in lycia's post these are definitely not juvenile salmonids. I work with these things daily and that's definitely not what they are. There's no parr marks along the sides for a start. If I have missed another photo (my browser is quite old and has a tendency to omit photos from forum posts) then apologies.
Yes I work with them too. I agree that parr marks would be expected so it's strange that they don't have them. However it is possible they could've lost their parr marks and are young adults (albeit very small).
Even without parr marks the markings are nothing like salmonids. Also the white and red spots are nothing like I've ever seen on any of our specimens. And the fact that they have stopped growing as small fish closes the book on salmonids for me.
It's more likely this. Phoxinus bigerri
. An Iberian minnow. http://en.wikipedia.org/wiki/File:Phoxi ... by-dpc.jpg
The distribution doesn't match as it is typically found in mainland Europe in France and Spain but, what with climate change it's not beyond the realms of impossibility that warmer water species can be introduced and thrive in the UK. There are plenty of records to suggest that it's geographical range is spreading on mainland Europe so it is certainly adaptable. Habitat is described as streams and creeks in foothills with clear and cold water, and gravel to stone bottom.
Oh, and it seems the white spots are spawning turbercles, a spawning characteristic seen in the males, probably as a result of hormonal imbalances. These are characteristic of the whole minnow family.