Two-Tone Fish

[Steve Baker]

I have read all of the comments here and i was just wondering if any of you have a garden pond? If you have and your golfish breed you will notice that they are all black when they are fry, and then they turn gold as they grow, now occasioally they dont turn due to environmental or genetic conditions and you can get a few black and gold fish. Ahh i hear you say no small fish are two toned, but how many of you study small fish in detail? do you photograph them? ect.... After all humans are not all the same colour and genetic defects do occur.

 

[GrahamM]

Actually, a genetic defect, at least in the colour changing mechanism, is as good an explanation as anything that's been put forward so far.

Makes a lot more sense than 'massive trauma', etc. But so does every other explanation I've heard.

 

[DAVE COOPER]

Following on from what Steve said, if you release ornamental type carp into the wild, I believe their offspring will, after a couple of generations, revert back to a more natural brown coulour. E.G the brown goldfish is a prime example that is now being confused with our crucians.

Ornamental carp are actually genetic freaks that are deliberately bred for these characteristics. Two tone bream and carp could quite realistically be natural genetic defects that surface periodically in the successive generations.

 

[Steve Plant]

Hello all. This is my first contribution to the forum (only got a PC recently). Just been looking at my slides of two tone captures (five fish between approx 4.5lbs & 11lb from two different waters). Most points raised so far have referred to "larger" bream, ie two toning does not seem to be as evident in smaller fish. My smallest two tone was a fish of approx 4.5lbs, this was a classic very distinct two tone, taken from a water where a bream below about 7lbs is a rarity (myself & friends over several seasons caught well over 100 bream to 11lbs with an average weight of 8-9lbs). Although this could be an one-off, (but then two tones don't seem that common anyway), it is obviously not solely confined to the larger specimens in a given water. What have other contributors found?, I would be interested to find out what weight of fish everyone is referring to when talking of two tones.

 

[GrahamM]

Steve, welcome to the Forum.

When I've referred to smaller bream I've meant fish less than about 2lb. I know 4lb to 5lb bream are not big compared to doubles but in this context they're not small ones, if you see what I mean.

I've had a quite a few two-toned bream in the 3lb bracket.

 

[keith miller]

I too have only caught two tone bream in Ireland, on the Shannon. They are uncommon, but in each case they were two tone on the left flank only, so colouration arising from burying in mud is unlikely. I think genetics is the most plausible explanation.

 

[GrahamM]

I had a word with Paul Garner today and asked what his explanation was for two-tone fish. He said:

"Quite frankly the explanation put forward by John Bailey, that the two-tone effect is caused by lifting fish from the water is crap, like most of what he wrote in the same piece.

"One explanation is that it is caused by damage to the central nervous system. This is correct in a few cases.

"Two-toning has also been caused by electro fishing, but again only in a few instances.

"The explanation that applies in most cases is that it is caused by a problem with the fish's brain. Normally, when light enters its eye, the fish subconciously begins to change colour to suit, but in a two-tone fish with brain damage or a brain defect, the signal is misunderstood and the two-tone effect occurs."

 

[Steve Baker]

So if it is remotely possible that two toned fish is caused by damage to the brain this explains alot of what has been said. First of all you say that it is larger fish that have only been affected, which means the larger the fish are the older they are as a rule. Also as the fish get older like any animal the lose brain capacity and so may become two tone. The only thing that wrong with this theory is that the fish we are talking about have a distinct straight line seperating the two tones. If the were spoty all over would we notice them and say they were two toned? Nope just unsual. However if JB was correct the carp he caught must have been dangled half in and half out of the water for a while to get a two toned fish like that.

 

[Steve Baker]

Sorry what in the first bit was that if it is direct damage to the brain how can anglers cause this with hooks as i dont know of any angler that has caused brain damage with a hook or line. Do you?

 

[Phil Hackett]

Hi there Graham I'm doing this late,in sort, Bailey's theory is totally unsoun.I'll post a full explanation when I have the time.

Later The Gadgit

 

[GrahamM]

Hi Phil, good to hear from you again. Will be interesting to hear what your conclusions are about this two-tone business.

NOTE: Phil Hackett was always known to his buddies as Phil The Gadget, being as he was always inventing things and making home made gear. He fairly recently got his degree in fish biology (or something like that) so what he'll have to say, like Paul Garner, will be from a scientific point of view.

We'll look forward to it Phil.

 

[andrew jackson]

Can't wait for Phil's conclusions.
Non of the explanations given so far seem right. My Bream fishing has been fairly limited, yet I have caught a number of two toner's. May be a more common occurance in particular waters or strains of fish? Without doubt the most interesting two tone fish I have caught was a twenty one pound common carp. This fish had the two tone just on one flank. Being a known fish, we can conclude that, it is two tone all the time. This would suggest that the stress theory is not correct. Parasite infection does not seem feasable either. Shurley after a period of time, other fish within a given water would be infected. So why does that lake only have one two tone carp.

 

[Ron Clay]

Oh yes please Phil - can't wait for your report

 

[Phil Hackett]

Sorry guys you'll have to wait a little longer as I can not transfer the document from Word onto this page.
HELP!!!!

 

[Carp Angler]

Try ctrl+c
then ctrl+v

 

[GrahamM]

You're up early Rik, or haven't you been to bed yet?

I've written to Phil and asked him to email his piece to me. If it's long (and knowing Phil it will be!) I'll put it on site as an article and then link it to this thread.

 

[BUDGIE BURGESS]

Great stuff, looking forward to reading Phils views.

 

[Phil Hackett]

I stated that John Bailey?s comment were totally unsound in my short last posting. I?ll now explain why I think this, but before I do I would like say. ?I know John is passionate about the welfare of fish and has penned many articles over many years on the subject.? That said, I think his article is another attempt by him to ram home the welfare message in a mag aimed at newcomers and novices to the sport. I congratulate him for penning it, but as I stated, I think its unsound and way off the mark.

My main fishing interests over the last 25 years during the summer months has been bream and tench fishing. Like Graham I have caught and witnessed many hundreds of bream, and seen many dozens of two-tone fish, both on the bank and swimming and feeding in the water. I?ve also seen several one sided two-tones (dark on one side, two-tone on the other) from different waters.
In regards to the phenomena, I have never come across any scientific literature that makes reference to why this happens. So therefore it is most likely that all comments on the issue are speculation and opinions.

If anyone wishes to give me 30,000 quid to research it as a PhD Question, I?ll be happy to oblige them!
Um! ?. thought not!
Worth a try though!
So here?s my thoughts/opinion on the issue. I suspect that two-toning may possibly be age related. Bream undoubtedly go darker as they get older. Most of the darker fish I?ve caught have been old fish, showing signs of body fat loss and having the general appearance of being out of condition.
Last season I followed a huge framed dark distressed fish down a mere in a boat. At no time after I first spotted it and caught up with it, was I more than two yards away from it. The fish was clearly on it way out and it subsequently turned up dead two days later. It weighed 10.4 dead and was one of the darkest fish I?ve seen alive and dead.
(Note: The water is syndicate controlled, and a fish and boat booking log is kept. The log showed that no member had been fishing for a week. The log also showed that no bream had been caught or hooked for three weeks. Therefore stress was not a factor with this fish)
Based on its frame size and the known weight that the fish can, and do go to in the mere, it?s likely to have been 14-15lbs at its peak. Coincidentally, it had grown for 11 years according to scale and operculum bone (Gill cover) ageing. However, it?s true that fish do live longer than the age shown on the scales & operculum. In the case of bream it is likely to be 8-12 years older.

Many of the fish I have caught and found freshly dead on waters where it is known that the stock is ageing, have been dark fish. On such waters I have also seen caught, significant numbers of dark fish with a fair number of two-tones amongst them.
It is therefore my view that the pigment in the fish?s scales stops working for some reason, which is as yet unknown. Two ?toning is I suggest, a product of this. Why in the main, two-toning should manifest itself at the rear end I have no suggestions. Other than the key to this understanding must lie in, ?Why do fish as they get older go darker??



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[Phil Hackett]

Yes! you are right Graham it is long and perhaps should have gone as article. That said, there's some good lads out there with good info. Cheers Carp Angler it work a treat.
Until later The gadgit

 

[BUDGIE BURGESS]

Thanks for sharing your opinions with us Phil.It was well worth waiting for.I think that peoples opinions and theories based on either scientific knowledge or long term experience are always interesting.It always anoys me when people claim theories as facts or invent "Psudo Scientific"facts.I certainly do not know if you are correct or not but your observations are more in line with what I have seen than some of the other rubbish.Once again many thanks for taking the time to post this.