Managing a Crucian Fishery - Peter Rolfe

One reason that good crucian fishing is difficult to find is that the fish itself has particular requirements if it is to do well. 

In (1) I set out those requirements. In (2) I look at various stocking situations, suggesting how they will best work. 

(1) There are four facts to remember. 

  • First, crucians in the right conditions produce abundant fry. 
  • Secondly, they spawn after roach and perch and their fry suffer badly from the competition. 
  • Thirdly, pike and perch and perhaps other predators like chub, zander and catfish, eat crucians in preference to other species Perhaps they prefer the taste of crucians, or perhaps the life-style of crucians makes them particularly vulnerable. 
  • Fourthly, crucians readily interbreed with goldfish and the resulting hybrids in time crowd out the parent species. They also interbreed with common carp. 

(2) Different stocking situations 

(A) A water containing no fish Here you can easily create an instant crucian water by putting in high numbers of biggish fish although this would be too expensive for most. Alternatively you can introduce good numbers of small fish (3” – 5” for example) or fewer brood fish. Crucians will normally breed prolifically in such a situation. Introducing young fish will postpone this. Do note, though, that stunted fish may be small but can also be very fertile. By netting you can control the numbers of your crucians to provide the sort of fishing you prefer, big bags of smaller fish or fewer, bigger fish. Your “problem” is more likely to be too many fish rather than too few. Tench are a good companion fish for the crucians as long as their numbers are controlled. Avoid predators and even benign fish like roach, for the reason given above. 

(B) A mixed fishery already containing pike, perch or other predators In such a pond or lake establishing a crucian population will be very difficult. 

The fish you introduce will be severely reduced in numbers by predation and numbers of surviving fry will be small because of competition from the young of other, earlier spawning species. If your predators are just small perch then stock with crucians too big for them to eat. Annual stockings of crucians may be more affordable than one or two mass introductions. In either case it will be some years before results are seen. 

(C) A mixed fishery without predators Here your stocked fish will be no more at risk that other species but recruitment is likely to be limited for the reason I’ve already described. The solution is repeated introductions until you build up the head of crucians that best suits the sort of fishing you require. 

General points

  • It is possible to introduce crucians to a carp water but they may well hybridise, though this is by no means certain. However, you will still have your original fish to catch. Repeated introductions will in time build up a good stock of crucians but their young may well not be true. 
  • Never mix goldfish and crucians. Hybridisation is certain and prolific. Hybrids will quickly dominate your pond. 

The nursery pond 

Several times I’ve mentioned the desirability of repeated introductions of crucians. Buying those fish is expensive. Consider the possibility of growing your own crucians in a nursery pond, one given over exclusively to the species. Such a pond does not have to be very big or very deep. It is possible to raise thousands of small crucians in a pond no more than 15 yards in diameter and with no more than 4’ of water. Digging such a pond is relatively cheap and quickly pays for itself.

Also, you have absolute control over the quality of your stock. Make sure your brood fish are genuine crucians. Stock with three or four males to each female. If they cannot be sexed with certainty, put in enough to make a mix of the sexes likely – say 40 fish. Do not introduce any other species. A small pond will produce only small fish, of course. If you have a bigger, growing-on pond you can produce bigger stock and at the same time provide some “dads-and-lads” fishing. In such a pond you can add tench for variety. If you don’t put in any other species you will have the bonus of spawning in this pond too.

Digging ponds of any size provides marvellous habitat for a wide range of other creatures and plants so you’ll be doing your bit for biodiversity as well. Finally… You must tell the Environment Agency what you are doing because there are certain permissions to get. Just as importantly you can ask them for help and advice.

Peter Rolfe