| MARK WINTLE |
| Mark Wintle, an angler for thirty-five years, is on a quest to discover and bring to you the magic of fishing. Previously heavily involved with match fishing he now fishes for the sheer fun of it. With an open and enquiring mind, each week Mark will bring to you articles on fishing different rivers, different methods and what makes rivers, and occasionally stillwaters, tick. Add to this a mixed bag of articles on catching big fish, tackle design, angling politics and a few surprises. Are you stuck in a rut fishing the same swim every week? Do you dare to try something different and see a whole new world of angling open up? Yes? Then read Mark Wintle’s regular weekly column. |
TRUE CRUCIANS?
By Mark Wintle, with lots of help from Andy Nellist
| In last week’s Wintle’s World, ‘Fickle Crucians’, I described the frustrations of trying to catch big crucians. But there was a second frustration on this water in that determining what were and weren’t true crucians was far from simple. And what about those fish that were distinctly suspicious, exactly what are they? With the existence of brown goldfish, hybrids between goldfish and crucians, and hybrids between common carp and crucians, and potentially complex back crosses there is plenty of opportunity to catch something that looks like a crucian, but isn’t. I would like to think that with the experience of catching thousands of crucians from a variety of waters I would have little difficulty in identifying a true crucian. Alas, when dealing with such closely related species as goldfish and crucians, the possibility of hybridism and back crossing with the original parent species (ie, fertile hybrids) makes identification extremely difficult. It is not too difficult to identify the obvious goldfish, and carp x crucians or carp x goldfish usually stand out due to presence of tiny barbules. But in a lake such as the one I have been fishing, with a mixed-up stock, even those comparatively rare fish that do look like true crucians must be treated with suspicion. So out of the five fish over two pounds I caught, only one might have been a true crucian.
Let’s start with a historical perspective. Immediately the problems start. No one knows for sure where crucians originated from, or if they were introduced into this country. Previously, the considered opinion was that they were probably brought from the Caspian Sea area during the seventeenth century. Alwyne Wheeler, however, believes that crucians are an indigenous species: Fisheries Management & Ecology Quote: Gibel carp? Since then, there have been countless further introductions. To add to the confusion there is also talk of gibel carp, Prussian carp and what the Italians call Carassio. It has long been suspected that gibel carp were not a separate species but were hybrids. The gibel carp investigated by the Hull researchers were in fact either triploid brown goldfish or crucian x brown goldfish. Add in the numerous imports of goldfish, including many that failed to change to the characteristic red/gold, and the selling on of brown goldfish as crucians for stocking, and the capacity for confusion is unlimited. Ornamental goldfish are in fact brown goldfish and when they spawn produce mainly brown offspring. No wonder unscrupulous dealers saw an opportunity to offload brown goldfish as crucians to the unwary. There are a few waters with a stock of crucian carp that have remained ‘pure’, but also there are many more waters that have a mixture of fish from a variety of sources. It gets worse Not only do we have two similar species in abundance, we also have two species that are closely related and that share similar spawning habits. The result is – hybrids. Can it get any worse? Yep. That close relationship between the two species including the similarities in spawning habit increases the possibility of F2 hybrids, including backcrosses, even further. Surely, it can’t get any worse? I’m afraid it does. Because carp, crucians and goldfish have been artificially reared for many years, especially on the Continent, there has been much selective breeding to achieve particular characteristics. This is why we have mirror carp, fantails, etc, and this is why we have what are simply bigger breeds of fish than the original wild varieties. It also means that the propagation of hybrids is also more likely. Don’t forget that crucian/common carp and goldfish/carp hybrids are also possible. The repeated stocking that takes place on many modern commercial waters further confuses matters, and the acceptance of fish for stocking with fish described as ‘crucians’ when they are nothing of the sort.
Summer Pit So why are the BRFC apparently prepared to accept fish from Summer Pit and the source lake (henceforth known as the Stock Pond)? The answer is that a sample of fish was taken from the Stock Pond in the 1990’s, and these fish were subjected to post-mortem analysis of the pharyngeal teeth and the colour of the gut lining. Apparently, there are also no fish that the crucians can hybridise with in Summer Pit. No such analysis has previously been carried out on record-contending crucians from other waters, and therefore a perception has been established that crucians caught from other waters would not be acceptable. During the research, however, seventeen of the waters that were sampled produced only crucian carp. So, are the BRFC right to accept crucians from Summer Pit and the Stock Pond? The research from Hull would suggest that the BRFC approach is flawed for a number of reasons: 1. Out of 24 waters surveyed in the research 17 produced samples that contained only pure crucians. 2. A number of fish were found that were post F1 hybrids (they had at least one parent that was itself a hybrid). The tests on the Summer Pit fish assumed that post F1 did not occur in wild populations. 3. The fact that post F1 hybrids exist means that there will be some crucian hybrids that look very much like crucians and will be very difficult to tell from true crucians other than by DNA testing. 4. A water that produced only crucians in a sample may still contain hybrids. 5. The waters that produced hybrids also contained true crucians. The crucians in Summer Pit came from the water that had previously held the record (the Stock Pond) and it appears that it is from this water that Martin Bowler’s pending record claim with a 4 lb 9 oz fish was caught earlier this year. These two waters appear to be the only waters from which the BRFC will currently accept a record. So why is what the BRFC do important? The answer is simply that if the BRFC take a stance on the identification of fish the angling world will follow and pull its socks up. The present policy on identification puts Summer Pit on a false pedestal as a crucian Mecca when in fact there are probably a number of other waters that could produce true crucians approaching or even bigger than the existing record. There are still plenty of crucians around There may be some that won’t like this but from my considerable experience, and this includes a number of fish dealings with Peter Rolfe in obtaining crucians for stocking, I think that there are a lot more true crucians around than some are trying to have us believe. But in the vast majority of cases when you do find true crucians, they will be small fish of less than a pound. That some waters that previously held only true crucians now have a mixed-up stock is certainly true but that does not mean that none of the fish now present are true crucians. It does mean that each fish has to be judged on its merits. Why don’t we see many more crucians? I think it’s because that unless you fish specifically for them, including location, method, etc, you simply won’t get them, hence their presence is often unsuspected.
What is true is that very, very few waters hold really big, true crucians, ie, over four pounds, and that for every true crucian over this weight twenty are reported that are not crucians at all; brown goldfish, hybrids, whatever. Conversely, if you are lucky enough to find some true crucians, cherish any that make it over two pounds, for you are a lucky angler. DNA? The latest news that a project by Hull University has discovered genetic markers that can be used to distinguish crucians, brown goldfish and their hybrids is good news as far as determining a true record crucian is concerned. The previous requirement of a post mortem on a fish caught from a water other than Summer Pit and the Stock Pond meant that the fish could not be returned, hardly what most anglers desired. This can be extended to a number of other species. Action for the BRFC With a method that has potential to determine even tricky post F1 hybrids, the sooner the BRFC adopt a procedure for obtaining a couple of scales from potential record fish the better. Of course, it is essential that it can be proved that the sample came from the potential record (hence the use of scales and not fin clippings) rather than a different fish, otherwise all you prove is that the sample was from a ‘pure’ fish. Clearly, given that the Hull research revealed that hybrids are not only fertile but are breeding in wild populations, it is now essential to identify all of the following: – crucians, brown goldfish (assuming anyone would want to claim such a record), roach, rudd, silver bream, bleak, and seatrout. It now seems that the BRFC will have to accept the inevitable and insist on DNA testing for claims for these species. This will allow a true specimen from any water to claim the record. The fact that we will then be able to see which fish failed the DNA test and those which passed will provide a useful yardstick to anglers against which to judge the identity of their catches. Action for the Environment Agency The EA are developing a crucian carp conservation plan that should ensure the survival of true crucian stocks in the future. Furthermore, they will be issuing a field guide to give anglers and fishery managers detailed information on identifying crucian carp. See FISHINGmagic news report ‘Crucian Carp Threatened by Goldfish’.
Conclusions Phil Smith, the BRFC trouble-shooter, is still wrestling with the problems of how samples could be collected and who would do the testing. Phil, however, acknowledged that DNA is the future. “We have got the beginnings of a method,” said Phil. But it is now two years since the BRFC were first made aware that technology was rapidly advancing to the stage where the species of a fish could be accurately identified from a single scale. With genetic markers now identified, it is today possible at a minimal cost to check to a high degree of accuracy a potential crucian record using a single scale. One idea that has already been mooted is to ask the EA to print a number in bold on the front of all rod licenses to phone if you think you have a record. This could then be used to instruct the lucky angler on what to do to ensure a successful claim. Ian Welch of RMC Angling welcomed the latest EA sponsored research from Hull university and said, “DNA analysis is the only way that we will ever move forward and it is the criteria that the BRFC should be using in future record claims.” Whilst Ian believes the population of Summer Pit and the Stock Pond consists only of true Crucians, he will be arranging for DNA testing of the fish. He stated, “I do not believe there is the possibility of F1 hybridisation from either of these waters as there are no species present with which the crucians are able to breed, but only DNA will confirm this!” Such a forward thinking approach from the man in charge at RMC Angling has to be welcomed. NEXT WEEK IN WINTLE’S WORLD: ‘Hemp and Tares’ |
