Costia/Ichtyobodo
Image from Brunel Microscopes
Better known to the fish keeper as COSTIA, invisible to the naked eye, this parasite is a killer of fish and we should not take it lightly. It is an 'obligate' parasite which means it relies solely on the fish for its existence, it cannot survive for more than 1 hour without a host.
It is a very small bean shaped protozoan parasite with two long thread like hairs protruding from its head, which are called flagellae. These serve two purposes; firstly they beat rhythmically which allows the parasite to move freely around the surface of the fish. Secondly and more sinisterly they puncture the skin cells and gill tissue to allow it to suck out the cellular contents.
Large numbers of Costia cause severe damage, leaving the body open to infection, often resulting in ulceration. The effect on the gill tissue is to cause excessive growth,which in turn causes the lamella to fuse together, this leads to loss of ability to defuse oxygen from the water.
Costia is a debility parasite, which means it is generally more active on a fish that is already in distress. It may well be that if you were to take mucus samples of a number of fish; you might only find Costia on the sick fish. Under those circumstances isolation and medication of the one fish may all that is needed.
The immune system of a healthy fish will cope very well with low numbers of Costia, which are usually found in the scale pockets of Koi.
Signs of infection are; scratching, leaping, clamped fins, swaying movements followed by loss of appetite and lethargy. A grey-blue haze may be seen on the body of the fish or the skin may be inflamed. For identification a mucus scrape is needed, being viewed through a microscope with a minimum 300x magnification. The parasite dies off quickly under the heat source of the microscope.
The whole lifecycle of Costia takes place on the fish, its reproduction is both sexual and by longitudinal fission (it divides lengthwise).
Costia has a very wide temperature range, 2 C to 29 C (35 F to 84 F) and can be very active on hibernating Koi. Although it is more likely to be a problem at the higher end of the temperature range.
Once favourable conditions occur, rapid infestation takes place, fatalities usually occur quickly without any outward signs.
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.
It is a very small bean shaped protozoan parasite with two long thread like hairs protruding from its head, which are called flagellae. These serve two purposes; firstly they beat rhythmically which allows the parasite to move freely around the surface of the fish. Secondly and more sinisterly they puncture the skin cells and gill tissue to allow it to suck out the cellular contents.
Large numbers of Costia cause severe damage, leaving the body open to infection, often resulting in ulceration. The effect on the gill tissue is to cause excessive growth,which in turn causes the lamella to fuse together, this leads to loss of ability to defuse oxygen from the water.
Costia is a debility parasite, which means it is generally more active on a fish that is already in distress. It may well be that if you were to take mucus samples of a number of fish; you might only find Costia on the sick fish. Under those circumstances isolation and medication of the one fish may all that is needed.
The immune system of a healthy fish will cope very well with low numbers of Costia, which are usually found in the scale pockets of Koi.
Signs of infection are; scratching, leaping, clamped fins, swaying movements followed by loss of appetite and lethargy. A grey-blue haze may be seen on the body of the fish or the skin may be inflamed. For identification a mucus scrape is needed, being viewed through a microscope with a minimum 300x magnification. The parasite dies off quickly under the heat source of the microscope.
The whole lifecycle of Costia takes place on the fish, its reproduction is both sexual and by longitudinal fission (it divides lengthwise).
Costia has a very wide temperature range, 2 C to 29 C (35 F to 84 F) and can be very active on hibernating Koi. Although it is more likely to be a problem at the higher end of the temperature range.
Once favourable conditions occur, rapid infestation takes place, fatalities usually occur quickly without any outward signs.
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.