"Hikui" 12:03pm Tuesday 5th Nov | message edited 6 times
joined: 28th Jun 05
last here: 11:00pm Monday 18th Nov
from: West Yorkshire
I have a fish that has developed a patch of Hikui this year. I'd just like to know a bit more about it.
1, Is there any way to get rid of it?
2, Will it spread to other areas of Beni or just the one patch where it is on the head?
3, Does it have any other effects to the fish apart from looking unsightly?
I seem to have messed up with the pictures as they don't enlarge when clicked on. Any ideas what I've done wrong?
I emailed Lincolnshire Fish Health enquiring about the cauterising paste mentioned in the Duncan Griffiths article and also attached the photos.
Not sure what to do now, if anything. Will see what more I can find.
Anyway, here's their reply:
As a laboratory we are unable to diagnose any disease from a photograph as this requires an examination or biopsy . Naturally there is speculation on the Internet.
I attach some information that may help as Hikkue is confusing . We have not made the cauteriser since 2005 and we would not suggest it is used on any skin lesion until its nature is known . If you would like to discuss the health of the fish further do contact Dr Paula Reynolds .
Dr Paula Reynolds
Lincolnshire Fish Health Laboratories & Research Centre
Hikkue is loosely translated as red gone and when applied to koi refers to the loss of red or hi skin colouration. There are various reasons for colour loss and as a result Hikkue has become the term applied to several causes. Often the loss of red pigmentation is due to a genetic predisposition inherited through the parent fish and if the skin remains normal after the red area has gone then it is down to nature. Years ago, a parasite known as the “Hi-eating worm” was alleged to cause Hikkue by feeding on the red cells despite ample evidence that no such organism existed. Stress is yet another factor and I have seen a pond of stunning Tancho's lose their red pigment cells when their pond accidentally drained of water overnight. Sunburn can cause skin blisters that in most cases heal without intervention. In severe cases such blisters may need the application of an iodine based product to prevent infection. Wild carp live in green water that prevents the more damaging rays of the sun penetrating the water. Koi live in of gin clear water and it is a fact that some can be over exposed to the rays if they favour the surface when swimming or sun bathing. and it is well known that the Japanese favour mud ponds over gin clear water.
There are now various diseases under the umbrella term Hikkue and it is obvious that the experience of koi keepers told they have one koi with Hikkue cannot be the same as a case in which several koi are afflicted with skin lesions and the fish are lethargic and mortalities have occurred. Comparing lesions or photographs of lesions is not a diagnosis. In my laboratory we apply the name Hikkue only to skin cancers and a tissue sample can be tested to detect antigens in the cells. If cancer is confirmed the disease is specific to the infected koi and poses no risk to other fish. A koi can live for years without secondary problems with this type of cancer and there is no need to euthanase the fish. Whilst cases of cancer can result from extreme sunburn the sun is not the only cause of skin cancer in koi and the over use of chemicals also has a role. The pigments in the colour cells have a slightly granular texture and their retention is supported by a balanced diet including adequate levels of carotene and spirulina. All the pigments we see in koi can redevelop following an injury depending on the degree of skin damage, and despite its vulnerability, this includes the red pigment. Water parameters also play a role in colour preservation, and each koi variety has its own unique needs. The carbonate hardness, mineral content, pH, as well as the temperature range the fish live within can all influence colour retention to a degree. Acid rain and chemicals are also factors in colour maintenance. The red colouration may be a stunning feature but it is notoriously unstable even in healthy koi. The capacity of cells to alter pigmentation means koi may be in their middle years before their skin is regarded as stable. In some varieties colour diminishes in the later years and this suggests some koi may be at their peak for relatively few years. Koi Judges look for colour conformity whereas I look for koi that are off colour as, a slight decrease in their overall colour intensity can suggest either a health or an environmental problem.
thanks for the reply and the information given, that's more or less what LFH said.
I would suspect genetics, there's a pergola over the pond and we've not exactly been blessed with too much in the way of sunshine this year to cause any problems.