Fish parasites and their effects

Hi
Jumping- This behavior might suggest the fish is suffering from parasites, or even poor water conditions. When the pH is dropping fish will jump because the water is irritating to their skin. So the first thing is to check the water conditions. If they check out fine than you would want to consider parasites. Flukes especially can cause jumping. So always establish water conditions and then treat for parasites.

Can any one confirm the above that parasites do make fish react this way?
What other types of infections/parasites make fish jump?
Does the lack of oxygene make fish jump?

Stuart,
I suppose It's possible but it's not likly to be the reason, there are other factors which can be a cause of this type of behaviour.

Fish jump because they want to, it can help dislodge silt/weed or any other debris collected in the gills whilst feeding. It can also be a reaction to contact with another fish whilst basking just under the surface or even a shaddow passing over them in this semi concious state, or just because they're happy.

Flukes and other parasites (including most single-celled protozoans) cause the fish to flick against under water structures like rocks , weed/reed or even the bottom trying to scrape them off, if a fish becomes overwhelmed by the amount of parasites then it will use all it's energy to repair the damage they cause. This will see the fish produce excesive slime and if the outbreak isn't dealt with the fish will lie dormant and become listless and probably die.

Low levels of oxgen will see the fish lie sub surface moving very little and gasping at the surface film, they tend not to expend energy and move very little.

However, the statement about the water conditions was a little misleading as a change in p.h. can cause the fish to dart around in short bursts due to the poor water condition (possibly an increase in nitrites or nitrates) irritating the fishes gills.

The fish are more likly to dart around as I said earlier but I suppose they could jump occasionally. This type of change can be caused by many things like a sudden increase in food or in Autumn leaves breaking down in the water but nature usually takes care of it.

Thanks Rodney for the reply.
Yep that makes sense to me what you have written.
I have heard that jumping can be fish behaviour if a parasite is on the gill area in an attempt to dislodge/clear the irritation. Not sure how true it was.

Many thanks again.

single-celled protozoans or parasites like gill maggot may cause a fish to jump but these won't be widespread so the infected fish would just be seen as one of the others jumping for any of the reasons in my last post.

Any fish which has these will need treatment as the excess mucus they produce whilst trying to heal the wounds caused will make the gills become sticky and supress the oxygen intake, the fish wouldn't really have much chance if there was a large number on it as all it's bodies defence system will be trying to repair these wounds to prevent infection and the rest of the fishes immune system becomes week and it can be attacked by any number of problems which ordinarily it wouldn't even notice or a predator will pick it off.

Thanks again Rodney for a great reply.

Just been looking into the Kio Herpesvirus which looks nasty. They don't class this as the same as SVC where if you discover KHV you don't need to inform the EA or the other organisations as yet. I hope this does not hit fisheries. I believe a PCR test carried out by CEFAS is the only true way of testing through molecular biological techniques.
Damn diseases, what a nightmare this importing of fish is. They say its hard to detect and there is currently no cure for this disease.
I do hope I'm wrong but I think it will pop up sooner or later.

Stuart,
Exactly right, the possible problem has been known for years about introducing fish without health checks, some people just don't seem to grasp the dangers..... or they simply don't care.

How often do you hear of people catching a fish from one venue and moving it to a nearby water? this may seem (to them) like a good idea but the dangers are real one fish can decimate an entire venue.

Also the amount of floods over recent years will eventualy help spread disease like KHV. Imagine buying a ?200 koi from a guy "getting rid of his set up" for ?50 and your pond being flooded by the river down the road how quickly could the river be overwhelmed, you could only hope that fish died with the sudden change in environment but even then would the virus spread if the carcass is eaten?

This reminds me of a disussion in a thread from a while back, you might like to have a look over Stuart......alan strickland's thread.

Thanks again Rodney, great link

I've been talking to a Koi breeder who is only worried about KHV even with me trying kindly to remind them of SVC. I find it hard to talk to this one person as they deal just in Koi and have no understanding of any of our native fish, I don't think they have heard of barbel or roach as crazy as it sounds. Its all pumps and clear water for them and off course the money side which is the main reason. Because they have no knowledge of coarse fish they have no understanding of what is happening to native fish and they truely believe a fish is happy in just a small clear tank. Ok I might be wrong but to keep fish like this in way too small size environment is not natural. I think the reply was the Japs do it so it must be ok.
They also would not know an SVC infection or the lawful responce to it. With no understanding of infections in their own country what chance do we stand to protect our native fish.
With fish stockist like this with a one attitude it can only be a matter of time before all hells breaks loose.

Sounds like he/she looks upon their stock as being safe from outside infection as they are kept in a controlled environment, but when they are released into the wild by someone who doesn't want them any more or a natural occurence it's not the issolated fish that's in danger it's everything else an infected fish comes into contact with.

Or someone taking a small pretty looking 'released' fish they've caught in a stillwater or river to someone with a pond, then SVC could enter the previously controlled environment, if this stock is then split up and sold several collectors now have a small epidemic.

Knowing what to look for when a virus is present is benificial but when it's dormant or the fish are immune and carriers with no obvious symptems then a sample biopsy by people like Cefas is the only way to get 'safe' stock.

That's the whole idea of section 30 consent but people only require this in fisheries, I wonder what certificates the fish breaders in the pets section of newspapers have?

Yep its that section 30 that I'm a bit confused on.
I have to obtain writtern consent before introducing fish to my fishery but its not needed for garden ponds. Reading the EA site is looks as if all fish stockings require this but they don't.
I did post this on anther thread but here it is again.

Before you introduce any fish into any water you must be in possession of a written consent from the Environment Agency under section 30 of the Salmon and Freshwater Fisheries Act 1975. This requirement applies to all waters except fish farms in England and Wales, including rivers, canals, reservoirs, lakes and ponds, whether public or private.
If the fish intended for introduction are not native to the British isles you will also need a licence under the Wildlife and Countryside Act 1981 and/or a licence to keep under the Import of Live Fish Act 1980, in addition to consent under Section 30.

Its the first section that I don't follow.
Reading it suggests even a private pond requires one. I am so confused by this. If its wrong should it not be made clearer.
The private pond must be like a garden pond.
If it is all fish then does that not mean that I should require one for movement of fish into my pond, I think you still need a fishing licence to fish your pond as well.
Getting very confused now
What would be stopping me from buying a large property, big house and large garden with say a 3 acre lake/pond then stocking it full of Koi then asking friends to join me fishing?
Getting even more confused now

Errr me too, but I tend to agree with you )