Trout colouration

Most of the 6-10 inch Brownies I've caught from my local river have been fairly dull looking. So they've had brownish flanks, with a few spots, but nothing striking.

The bigger ones I've caught though, 12 inches +, have been striking. Lots of spots, going right up to the gill covers and the head, and several red ones, which were missing from the smaller fish.

I've seen pictures of Trout for the Irish Loughs, the bigger Trout I'm catching are as striking as this. The smaller ones though; you's swear they came from a diffferent river altogether.

Anyone else experienced this?

The variation in colouration of brown trout can be enormous.

I have caught them in Derbyshire streams that have been almost black with just a few bright orange spots. I have also caught them from a few reservoirs where they have been bright silver and almost "seatrout" in appearance.

The variations are huge.

I think Ric is referring to the phenomenon of two distinct races of trout in the same river.

I have come across this before - some trout being (say) golden brown with just a few red and black spots, others being much paler with lots of spots (and no, I don't mean rainbows!) You can even find even some which are quite greenish with few spots - almost char-like - in amongst the others.

To give some examples, the tiny river Chess in Hertfordshire had (possibly still has) both the dark, lightly spotted type and the golden, heavily spotted variety. The upper reaches of the Western Rother have some very dark fish (the river flows through woodland at the end of my road) but also some very light, almost white-gold, specimens, which can be confused with the sea-trout which come up each summer. Two of the light-coloured trout have been holding station in the current above a nearby bridge the last few weeks.

Why there should be more than one colouration in the same stretch of river is open to speculation. I believe that environmental influences dictate the distribution of the various forms; shaded, tree-hung reaches often harbour the darker type, whereas the golden form is usually found over gravel where the sun penetrates. Presumably there is some occasional migration of the different types into the other's territory.