Ferox Identification

[ROBBO90]

What is the official method for identifying a ferox from a brown?
Size?
Weight?
Location?

[fergie68]

All of the above Rob.

[Neville Fickling]

I always thought it was a brown trout that lives in a glacial lake that eats fish.

[fergie68]

I always thought it was a brown trout that lives in a glacial lake that eats fish.

That's exactly what it is Nev.

We started classing a ferox as a trout from a large glacial or similar of 3lb and above caught on a deadbait or lure.

It's not scientific but it works.
Of course if your dealing with a Loch with fish cages on it that kind of throws a spanner in the works.

[Neville Fickling]

Well fish cages bugger s everything else up. I had a double figure brown from a trout Loch between Edinburgh and Glasgow from where the cages were usually to be found. The cages had been taken to shore but that fish didn’t notice. Only true Ferox ever caught by myself was on a dead in Ireland jan. 11 lb.

[fergie68]

Well fish cages bugger s everything else up. I had a double figure brown from a trout Loch between Edinburgh and Glasgow from where the cages were usually to be found. The cages had been taken to shore but that fish didn’t notice. Only true Ferox ever caught by myself was on a dead in Ireland jan. 11 lb.

Trolling or static Nev. ?

[Gary Coggon]

Fergie, am I right in somehow recalling Ferox85/Ferguson/Thorne/Greer et al using weight in the field, whilst working on LDH(100) allele as a lab marker of longevity - therefore ferox - as opposed to LDH(90) in non-ferox browns? Fin clip tissue samples, not scales?

(With apologies to OP - I realise that this biomarker stuff is no help whatsoever out on the loch…)

[fergie68]

Fergie, am I right in somehow recalling Ferox85/Ferguson/Thorne/Greer et al using weight in the field, whilst working on LDH(100) allele as a lab marker of longevity - therefore ferox - as opposed to LDH(90) in non-ferox browns? Fin clip tissue samples, not scales?

I will send that to Aya and see what he says . He's actually trolling this week so he might not answer right away.

[Gary Coggon]

Thanks - that’d be grand

[fergie68]

LDH100 allele is the genetic marker that Andy Ferguson associates with (calls) a ferox.
Scales can now be used as genetic samples.
I still believe it’s a lifestyle (any large predatory trout) that is that predicts whether it’s a ferox.
ie: a 15lb trout from Rannoch for instance, is a ferox, regardless if it has the LDH100 marker.
Otherwise - the only way to identify a ferox, is to get it genetically examined in a laboratory ??
Just got to look at some of the photos of trout from different Lochs and within the same loch to see the difference within a brown trout population.
I would like to see someone put a photo/description of a so called “proper ferox trout”

[Neville Fickling]

My 11lb brown was caught float legering a farmed brown trout about 7 inches long . It was one of the prettiest brown trout I’ve ever caught.

[BillCollins]

Even in small loughs, e.g. 500-1000 acres, there can be broad variations in spot patterns and colours.
They seem to have a liking for oily deads like mackerel and herrings in the early months post spawning, Jan and Feb.

[fergie68]

Even in small loughs, e.g. 500-1000 acres, there can be broad variations in spot patterns and colours.
They seem to have a liking for oily deads like mackerel and herrings in the early months post spawning, Jan and Feb.

Mackerel seems pretty popular with the Scottish ferox too Bill.
I've had plenty on trolled herring.

[Gary Coggon]

Thanks for following up with Aya, Fergie.
And I think you’ve coralled both main conundrums: old one being appearance of a typical ferox and the new one being reliability of a single allele’s presence/absence. Wisdom seems to be there’s no such thing as a typical ferox broad appearance apart from size. As for genetics, I know that around 50 genes are involved in determination of human longevity, would suspect (without a lit search) that at least a handful are involved in most/all vertebrates, so designation of ferox may end up involving assessment of a panel of markers. Would love to know where Aya et al have got up to with genetics.
Fascinating topic…

[fergie68]

Thanks for following up with Aya, Fergie.
And I think you’ve coralled both main conundrums: old one being appearance of a typical ferox and the new one being reliability of a single allele’s presence/absence. Wisdom seems to be there’s no such thing as a typical ferox broad appearance apart from size. As for genetics, I know that around 50 genes are involved in determination of human longevity, would suspect (without a lit search) that at least a handful are involved in most/all vertebrates, so designation of ferox may end up involving assessment of a panel of markers. Would love to know where Aya et al have got up to with genetics.
Fascinating topic…

50bwas the number we were looking for on tagging programmes Gary.

Aya and Ron are both now retired . Most of their work was done in their own time at their own expense. Ferox don't generate money so Salmon concerns were always top priority in their line of work.

If you use face book Ron isn't hard to find and he is as keen now as he ever was. I'm sure he would be only too happy to discuss his work.

[Gary Coggon]

[fergie68]

I'm wondering if Robb has caught a big trout.
Any chance of a pic.

[ROBBO90]

My mate had this on a 6" soft bait while we were pike fishing on a midlands res. But not knowing the official line for identification we assumed rightly or wrongly that when it ran the scales to 15lb it must be one..... or maybe not.

IMG_20230729_102214.jpg

[fergie68]

Lovely fish Rob. Big predatory brown but not a ferox .

[piker al]

I always thought it was a brown trout that lives in a glacial lake that eats fish.

That's exactly what it is Nev.

We started classing a ferox as a trout from a large glacial or similar of 3lb and above caught on a deadbait or lure.

It's not scientific but it works.
Of course if your dealing with a Loch with fish cages on it that kind of throws a spanner in the works.

Does the water have to have charr in for the browns to genetically change to ferox?

[fergie68]

No mate. They occur in other lochs that don't have charr all they need is a prey species that can be small trout ,white fish etc.

[ROBBO90]

Many thanks for the technical information. I'll go back to blanking for big eels. I would really like to catch a burbot from somewhere in the UK. I believe they have had a very limited stocking into one or two secret locations but info is very sparse on locations and stocking.