It's still a fish, innit.

[Vagabond]

Back in the day, hybrids were rare, and received wisdom was that hybrids were infertile, so back crosses with a parent species didn't happen.

 

Now, not only do fish farms foist all sorts of hybrids on their customers, but we have learnt that some hybrids can successfully hump anything with fins, so that finding a "pure" crucian or a "pure" roach is a bit like finding an honest politician. Of course, one can take the egocentric approach

 

"My water produces pure roach"

"Your water, unfortunately, has a past record of hybrids"

"He is just trying to pull a fast one"

 

...and now the problem includes rudd-bream hybrids.

 

Until this morning, as far as my catches were concerned, rudd-bream hybrids were confined to the Ireland of Bernard Venables day, apart from one instance in the 1960s where I had several from Gt Brickhill pond near Luton (one or two were verified by the British Museum of Natural History at the time)

 

This morning, fishing sink and draw for perch, (lobworms on a #4) under my favourite steep bank, amongst a mixed bag of perch, gibels, common carp, rudd and a fantail goldfish came this -:

 

 

The interesting thing was that this behaved just like the ones at Brickhill fifty years ago. Took a lobworm on the drop, about six feet down in eight feet of water close to the bank. Behaving like rudd, but deep down. I recognised the fish at once, but just to provide a bit more evidence, did a fin-ray count (from the photo) on the anal fin - 21 or 22 - substantially less than a bream. Comments from those interested in such things are welcome

 

As I unhooked it , I felt the rough tubercles on the head and shoulders, so whether it is fertile or not, it looks as if it at least has the intention of trying to "get its leg over" .

 

 

I just hope it is infertile - we have enough mongrels in our fisheries already.

 

Incidentally, because since the good perch of the first two sessions, recent trips have merely yielded nuisance carp (REAL nuisances, 7 and 8 pounders, big enough to make such a commotion as to ruin the swim for the morning. If I get nuisance carp whilst roach fishing, the tiny hook will straighten, but on perch tackle one has no option but to play the fish out - any ideas folks ?) I changed my tactics today to a moving bait to try to avoid the carp. Partial success - the only carp this morning was around a couple of pounds and soon hustled out, but the best perch only just scraped a pound. It was an interesting mixed bag though - moving baits bring all sorts of surprises.

 

 

 

 

Edited June 26, 2015 by Vagabond

[Vagabond]

This is the "real" thread, will add pics ASAP

[Mark Wintle]

Yes, it's a rudd x bream most likely.

 

Hybrids have always been around but the increasing stocking of 'F1's, usually crucian x carp, brown goldfish - waste fish from fish breeders, and ide which seem to have got into a number of rivers have made identification of fish more interesting.

 

I have a copy of a thesis done on cyprinid hybrids by Colin Pitts and it is probably much nearer the truth than many out of date angling books that claim that hybrids are infertile (mules ARE infertile).

 

Evidence of fish with spawn(female)/tubercles(male) doesn't mean that the hybrids will necessarily be especially successful in breeding ie fertilisation of the eggs and subsequent fry development. Yes, backcrosses, possibly triplecrosses and hybrid crosses are all possible but the evidence suggests that fish tend to breed true. Even in waters where there are hybrids it is often the case that the hybrids don't occur every year. there is evidence that although female hybrids have viable eggs the males are much less viable so even if hybrid eggs are fertilized by another hybrid or a true species fish then there is generally a very high defect rate and therefore very poor survival so claims of 10% roach/90% bream are mostly unfounded. The closeness of the relationship of the parent species may also have a bearing on this as some hybrids are viable in the lab but virtually unknown in the wild. What also muddies the water is that some fish and hybrids - silver bream and their hybrids especially, are rarely identified correctly as such. There is also evidence that hybrids are skewed in appearance towards one of the parents, thought to be the female which may explain why hybrids even with the same parent species vary considerably in appearance. In my two roach books, Big Roach and Big Roach 2, there is a lot on this subject as well as probably the largest collection of UK hybrid pictures (roach-related) published. The other book with a good handle on hybrids, this time relating to crucians, is Peter Rolfe's Crock of Gold.

[Kappa]

A water near me is full of various hybrids including some big roach that are almost certainly roachy looking hybrids.

 

I think I posted these before but I only catch these in the summer and only ever on prawns:

 

I thought they were rudd bream hybrids. The. buttery bronze colour of them is beautiful

 

[Vagabond]

.... there is generally a very high defect rate and therefore very poor survival so claims of 10% roach/90% bream are mostly unfounded. The closeness of the relationship of the parent species may also have a bearing on this as some hybrids are viable in the lab but virtually unknown in the wild.

Thanks Mark, for an informative post.

 

In general terms the above quote is vaguely re-assuring - added to which, in most natural waters , each species will have a preferred spawning habitat which would tend to keep eggs and milt from two different species apart.

 

The problem is that many commercial waters and most "managed" small ponds are so crowded that fish have very little choice in where to spawn. They are forced to spawn in close proximity with other species. The only possible way to keep milt from one species away from the eggs of another is for the two species to spawn at different times - and as we know, spawning times for a particular species can vary from year to year. Therefore, sometimes the respective spawnings of two different species may overlap in time, and sometimes not.

[corydoras]

I'd like to see genomes and the molecular genetics of some of these different "species" and "hybrids" of British cyprinids. Morphologhy is not enough on it's own these days.

[Mark Wintle]

Then you need to get hold of the Pitts thesis. I also helped with DNA testing sample of crucians and had little difficulty finding samples of true crucians from waters that also had hybrids. With roach, bream and rudd, experience of seeing the pure species on the basis of several times a week as well as catching 200-300 hybrids a year makes it far easier to spot hybrids than those who seem to rarely see hybrids. Occasionally you see a hybrid that is clearly a hybrid but being sure exactly what it is impossible without DNA.

I'd like to see genomes and the molecular genetics of some of these different "species" and "hybrids" of British cyprinids. Morphology is not enough on it's own these days.

 

The two attached are both probably roach related hybrids but unlike the usual roach x bream or roach x rudd hybrids.

Edited June 28, 2015 by Mark Wintle

[Vagabond]

Then you need to get hold of the Pitts thesis.

Have just done so, by signing up to the British Library EThOS.

 

After which you can download this particular thesis for free. I am just off to the IOM for a week's LRF, bird watching and sea-food eating, after which I will carefully read Colin Pitts's thesis.

 

Thanks Mark for putting me on to it.

Edited June 30, 2015 by Vagabond

[Steve Walker]

Off topic, but what a great resource. My thesis is not in it. It is in the equivalent system of The University of Wales. You can only register for free access to that if you live in Wales. Poor show.

 

(Not that I need a copy, was just curious)