Unknowing Cannibal ?

[Inchlaggan]

The Marine Scotland link in Mike's post (above) makes the most sense to me.
I do not doubt the "genetically different" comment but a lot more research will be required to demonstrate that a "ferox gene" exists (present in ferox, absent in brown), whether this is a dominant or recessive gene, whether hybrids exist, and how this gene manifests itself in the life of the trout. That plus habitat and range need to be considered.
In the meantime, release them carefully.

[Malcolm]

Edward Fahy explained this I think in the best way. You can divide groupings of trout in many ways one of the ways is life span.

He split trout up into long-lived and short lived groupings.

Long lived life strategies include

* Ferox

* Burn trout (though not all burn trout are of the long lived strain these are again unusual in that they produce much larger and much fewer eggs than normal

* Long lived seatrout - not all systems have these but those that do tend to produce much bigger seatrout. There are quite a few of these longlived seatrout fisheries in Wales and Scotland  but Ireland only a few. 

The long lived trout actually have a genetic component called  LDH-5(100) allele - the short lived trout instead have LDH-5(90) allele.  I'm sure Mr Fachan will be along soon to explain further as it was he who put me onto this in the first place.

As well as this Ferox are unusual in that they only spawn every second year and spawn in different places - normally in outflows - although that's not prescriptive.

Alan,

My reply as to whether Ferox can come from stocked fish was rather short but they did this in Norway when they hatched and stocked ferox. Ron Greer reports this in his excellent book on Ferox Trout and Arctic Char. This is one of the best books I've ever read.

[Wildfisher]

Ron Greer reports this in his excellent book on Ferox Trout and Arctic Char. This is one of the best books I've ever read.

It is a superb book written by a man who knows what he's talking about.