Ichthyopthirius Multifilis/White Spot
Image supplied by E.E.K Member
Quite a daunting title but better known to the fish keeper as White Spot or simply ICH. This ciliate protozoan parasite is the largest of the single celled protozoa's, which create a problem to our fish. White spot is very contagious and is considered as being the biggest single killer of fish worldwide. It is unbelievable that an organism of this size (approximately 1mm in diameter) can have the potential to be so devastating to our Koi.
By the time the fish keeper can see the actual White Spot it is already in its mature stage of the lifecycle and fatalities may already have occurred. They look like white spots that are about to burst and they do just that. To compound the problem the wound is an open invitation to secondary infection. What you are actually seeing is the mature parasite bursting through the skin of the fish; it undergoes a free-living stage and falls to the bottom of the pond. During that time it will form a jelly like capsule where it will reproduce itself thousands of times. Once the immature parasites have reached a certain stage in development, the capsule ruptures, releasing the infective stage of the parasite. On encountering a fish the parasite burrows under the skin to infect the new host. It takes just 30 seconds for these 'swarmers or to mites' to penetrate the skin. Once under the skin it becomes impervious to chemicals and grows safely to maturity. The parasite will often remain dormant within the fish until a trigger factor re-awakens it and the cycle will start once again.
Netting, handling and temperature fluctuation all can contribute to stress and these are thought to be the most common trigger factors required.
It is essential to have White Spot microscopically diagnosed because male Koi sometimes have a spawning rash, this is an arrangement of white pimples and these can be miss interpreted. These pimples are usually confined to areas around the gill cover, the leading rays of the fins and upper surface of the body. The spawning rash is quite distinct from White Spot in that the pimples are regularly arranged on the scales and fins, whereas White Spot is literally dotted randomly over the body surface.
Most male Koi would not thank their owners for dipping them in malachite green and wrecking their opportunity of reproduction.
White Spot can be brought into the pond environment by Frogs, Newts and on Plants, a very good reason why you should sterilise all plant life before placing within your pond.
Symptoms include vigorous scratching or flicking, hanging around oxygen-enriched areas, as the infection progresses the fish will stop feeding, become lethargic and may loose colour. Make no mistake, left untreated White Spot WILL kill your Koi.
The lifecycle is very complex and depending on the level of infestation multiple treatments may be necessary to cover the complete cycle. As with most parasites the lifecycle is temperature dependant, taking from 4-5 days at 27 C (80 F) to 4 weeks or more at 10 C (50 F).
When viewed under the microscope the parasite is slightly oval in shape, covered in tint hairs and is seen to slowly revolve around the field of vision. The characteristic feature of White Spot is the "horseshoe shaped nucleus" in the middle, the nucleus is the part of the cell, which stores all the genetic information. It can often prove difficult to see this distinguishing feature as it very much depends on the orientation of the parasite.
Constant improvements in medication are made to eradicate this parasite, please contact us for treatments and correct use of dosage for your pond and Koi.
By the time the fish keeper can see the actual White Spot it is already in its mature stage of the lifecycle and fatalities may already have occurred. They look like white spots that are about to burst and they do just that. To compound the problem the wound is an open invitation to secondary infection. What you are actually seeing is the mature parasite bursting through the skin of the fish; it undergoes a free-living stage and falls to the bottom of the pond. During that time it will form a jelly like capsule where it will reproduce itself thousands of times. Once the immature parasites have reached a certain stage in development, the capsule ruptures, releasing the infective stage of the parasite. On encountering a fish the parasite burrows under the skin to infect the new host. It takes just 30 seconds for these 'swarmers or to mites' to penetrate the skin. Once under the skin it becomes impervious to chemicals and grows safely to maturity. The parasite will often remain dormant within the fish until a trigger factor re-awakens it and the cycle will start once again.
Netting, handling and temperature fluctuation all can contribute to stress and these are thought to be the most common trigger factors required.
It is essential to have White Spot microscopically diagnosed because male Koi sometimes have a spawning rash, this is an arrangement of white pimples and these can be miss interpreted. These pimples are usually confined to areas around the gill cover, the leading rays of the fins and upper surface of the body. The spawning rash is quite distinct from White Spot in that the pimples are regularly arranged on the scales and fins, whereas White Spot is literally dotted randomly over the body surface.
Most male Koi would not thank their owners for dipping them in malachite green and wrecking their opportunity of reproduction.
White Spot can be brought into the pond environment by Frogs, Newts and on Plants, a very good reason why you should sterilise all plant life before placing within your pond.
Symptoms include vigorous scratching or flicking, hanging around oxygen-enriched areas, as the infection progresses the fish will stop feeding, become lethargic and may loose colour. Make no mistake, left untreated White Spot WILL kill your Koi.
The lifecycle is very complex and depending on the level of infestation multiple treatments may be necessary to cover the complete cycle. As with most parasites the lifecycle is temperature dependant, taking from 4-5 days at 27 C (80 F) to 4 weeks or more at 10 C (50 F).
When viewed under the microscope the parasite is slightly oval in shape, covered in tint hairs and is seen to slowly revolve around the field of vision. The characteristic feature of White Spot is the "horseshoe shaped nucleus" in the middle, the nucleus is the part of the cell, which stores all the genetic information. It can often prove difficult to see this distinguishing feature as it very much depends on the orientation of the parasite.
Constant improvements in medication are made to eradicate this parasite, please contact us for treatments and correct use of dosage for your pond and Koi.