Rainbows- do they breed?

[Ric Elwin]

Yesterday I caught at 2.12 Rainbow from the river Goyt, a tributary of the Mersey. It was a fantastic fish, had a full tail, certainly didn't look like a stockie. Anyway as far as I know, there aren't any Trout farms along the river.

This raises the question, where did it come from? I'm wondering whether Rainbows, having found their way into the river somehow, are breeding successfully.

I know that generally it's believed they can't breed in this country but there are exceptions, the Derbyshire Wye being one, apparently.

The Goyt is similar in character to the Wye and originates from the same freestone, so I suppose it shouldn't be such a suprise if they are in fact breeding.

Has anyone got any thoughts, or any experiences of Rainbows breeding?

 

[captain carrott]

if they are kill them quick before we become infested with yet another unwanted american invader.

 

[Fred Blake]

The River Chess in Hertfordshire used to support a breeding population of rainbows; I caught my first trout there - a fish of about six ounces.

I don't know whether they still breed, as the river has almost disappeared due to abstraction.

 

[Joskin]

My local river Windrush used to have a lot of Rainbow Trout in it. We used to catch them as kids and im sure they were wild and bred in the river as we used to catch plenty of tiddlers too.

 

[captain carrott]

the windrush has browns in it but not rainbows as far as i know.

 

[stuart clough]

They can breed in the UK, but rarely do succesfully. Most of the places I know where successful recruitment has taken place are immediately downstream of large reservoirs, where the water temperature remains cool in the spring.

 

[Joskin]

you are correct jason the windrush has mainly browns now but there used to be plenty of rainbows.

 

[Ron 'The Hat' Clay (ACA-Life Member)]

Of course rainbows breed in this country. In fact the River Wye in Derbyshire has had a breeding population of rainbow trout for many years.

There is evidence that rainbows have bred near the feeder streams of Rutland water and Grafham water.

Recently however the rainbows stocked in most British waters have been triploids, which makes them sterile and female. This has been done to avoid those nasty black fish which you can get at this time of the year which are not good enough to feed a cat.

 

[stuart clough]

Not sure I follow the logic though Rick. If you had caught rainbows of a range of sizes, including some small ones, this may point to a recruiting population. But a single capture of an adult fish doesn't suggest a breeding population to me.

Ron - what is the evidence of rainbows breeding near the feeder streams of Rutland and Grafham?

 

[Ric Elwin]

Stuart I guess I reached my conclusion because the fish had a full tail, and generally seemed wild. I could be wrong of course!

 

[Fred Blake]

Any rainbow which has been 'at large' for more than about a month should develop a full set of fins, unless it suffered an attack of furunculosis whilst in the stews. You can catch any number of the things from the Test in winter; by the time grayling fishing starts those which avoide capture during the trout season will have been on a wholly natural diet for a couple of months.

 

[Ron 'The Hat' Clay (ACA-Life Member)]

Caring trout farms with spacious rearing facilities can rear excellent stock fish with full fins. The stock trout going into Thrybergh reservoir are such fish. And this is a trout water run by Rotherham MBC which has some of the best value still water fly fishing in Britiain. I caught a 1 1/2lb blue trout there yesturday which zipped off at least 20 yards of line and jumped 4 feet into the air. A truly incredible little fish.

Certainly fin damaged trout do mend in time.

The evidence that rainbow trout in some of the big reservoirs breed is purely anecdotal. But certainly they used to go through the motions of breeding and certainly I do not doubt that some of the eggs hatched out.

I say "used to" because it's not likely to happen these days. First of all, you just don't catch cock rainbows any more because virtually all the fish stocked are triploids.

Actually I miss the big cocks with their impressive "kypes" and pugnacious appearance. A cock rainbow in good condition can be a most impressive fish. Tha last big Cock rainbow I caught was taken in South Africa, a country where natural breeding occurs in many rivers and streams.

It's easy to tell a triploid by the way. There is absolutely no sign of ova in the fish when you gut it. And they are all sterile hens of course.

 

[stuart clough]

I wouldn't be so certain that the some of the eggs hatched out, or were even fertilised correctly. There are many examples of rainbows going through the motions, but not succesfully producing offpsring.

As to triploids, they can be either male or female, but they are sterile. They are commonly produced by heat shocking the eggs at an early stage.

It is more common these days to stock with "all females" which are produced differently. These are produced over 2 generations by feeding hormonally adjusted food during the first couple of months. Half of the males become genetically female but still produce milt (sex reversed). Breeding from these sex reversed male fish then results in all female offspring.

 

[Ron 'The Hat' Clay (ACA-Life Member)]

Thanks for the expert comments Stuart.

I'm a little shaky on how triploids are formed.

 

[stuart clough]

No problem.

 

[Richard Baker 6]

Hi chaps,

This thread really interests me as I've thought that British rivers must hold breeding populations of rainbows for some time.

I've fished a number of rivers in North East America, mainly in New York state where I used to live. These rivers resemble the rivers of lancashire and derbyshire in many ways. The upper Ribble and Derwent come to mind. These rivers in the states have natural breeding populations of rainbows and browns living in harmony.

Traditionally there were four rivers in britain known to have populations of breeding rainbows. They were:

The Derwent
The Chess
The Misbourne
The Wye

However, I recently asked the question of how many streams in britain did have natural populations of breeding rainbows. The question was put to Charles Jardine, Paul Knight (Director of the Salmon and Trout Assiciation) and a representative from the EA at a meeting of the salmon and trout association (lancashre branch) The answer was interesting. Charles Jardine informed me that the ED have now recorded over 40 british rivers where rainbows are breeding successfully and year on year. A cold winter like we've just had will only help this.

I am not sure what I think of this. I love our native brown trout species, and don't think rainbows will takee over, or push them out as many people say as in the states they liv in harmony. I enjoy catching any wild trout in great condition. That said this could be an issue and I can see the view from both camps.

The other interesting thing? the Tay has a large breeding populations of rainbows, They have been caught from a few ounces up to over 15lbs by experienced anglers (Mark Bowler of FF and FT to name one). What happens when these trout decide to go to see and return as steelhead? a very interesting proposition.

This is a very intersting thread, would love to see what others think on this subject.
Rich

 

[Ron 'The Hat' Clay (ACA-Life Member)]

I for one would certainly like to see a few wild rainbows in the UK.

Many years ago the Eerste River in the Western Cape had wild rainbows that bred in the upper reaches and went to sea, returning as steelheads. Not now of course. This river has been polluted by wine farm effluent.

Now chaps, there is nothing, repeat nothing that swims in freshwater can beat the incredible fighting power of a steelhead. A overwintered reservoir rainbow is good, as is a fit blue trout, or a salmon, or a seatrout.

And don't even mention barbel, they are not in the same league.

But nothing comes near a steelhead!!

For this reason I would love to see some wild rainbows in our rivers with a penchant to go to sea.

Turbocharged dynamite!!

 

[captain carrott]

they should be wiped out before they get out of control.

 

[Ron 'The Hat' Clay (ACA-Life Member)]

Oh and by the way, both rainbow and brown trout can live in harmony. Typical examples are in countries like New Zealand, Australia and South Africa, parts of the world where thes fish were never indigenous.

 

[captain carrott]

that's just it they aren't in harmony with the browns they are in competition, not to mention all the other indigenous species which they will have a detrimental effect on.
they will reduce both size and numbers of indigenous fish.