Fish, Tanks and Ponds

Fish, Tanks and Ponds
A comprehensive guide to fish


Glass fish with lymphocystis
Glass fish with Lymphocystis

What are the symptoms of Lymphocystis?

Typically the infected fish will develop raised irregular lumps at random on the body, head, fins or tail. The lumps can be the size of a white spot cyst or they might encrust a large portion of the body. The lumps can be pale pink to pale grey in colour and due to their irregular shape the disease is often referred to as 'Cauliflower Disease'.

Is there a cure for Lymphocystis?

Because the disease is caused by a virus it could only be prevented by the use of a vaccine, unfortunately no such vaccine exists. So there is no treatment which will cure the disease.

But most infected fish will develop their own immunity to the virus and they will recover from it although this can take many weeks.

Even after recovery of the affected fish the disease could still be present in the tank and any new fish which haven't been exposed to the virus may show all the signs and symptoms of the disease until they have built up their own immunity.

What should I do if my fish have Lymphocystis?

The disease is only rarely fatal and the virus itself doesn't cause a great deal of illness, most fish will carry on as though nothing is wrong, they will have their normal energy levels and they will compete and feed as normal. The disease is fairly benign and is no worse than human warts.

But because of its random nature it can cause a problem if the mouth is badly affected because this could interfere with breathing and feeding, the gills could be affected and in this case it may prove to be fatal.

If the mouth is very badly affected then surgery may be the only way to save the fish, obviously this would have to be carried out by a Vet and shouldn't be attempted by anyone else.

As previously stated the disease will eventually be overcome by the fishes own defenses, when this happens the infected cells will drop off but they will leave an open wound on the site where they were. This open sore could easily become infected by one of the many background bacteria's which are ever present in water. To prevent this the tank should be treated with an aquarium anti bacteria product until healing has started.

Once the fish have recovered, is that the end of it?

In most cases yes, but new fish which have never been exposed to the virus may fall victim to it. Or if the fish become stressed due to poor water quality or bullying then their disease resistance will be lowered and they may show signs of the disease all over again.

What is Lymphocystis?

Lymphocystis is a common viral disease which affects all groups of fish, tropical, cold water, fresh water and marine. It is caused by an iridovirus which causes the host cells to become greatly enlarged. It affects the skin and the fins including the tail of the higher ray finned fishes.