Skin Fluke/Gyrodactylus
Image from Brunel Microscopes
There are more than 100 species of skin or body flukes found in the aquatic environment, but possibly the one most commonly found Fluke infecting the Koi pond is Gyrodactylus Elegans. Commonly known to the fish keeper as the Skin Fluke this parasite, which is not visible to the naked eye, will exist in low numbers on a lot of fish and normally does not cause any problems. It is in itself not the killer that it is sometimes held to be, but can cause many secondary problems that are killers. Fungal and Bacterial infections can easily take a hold at the sites of wounds made by this parasite. It is the fish version of a flea you might find on a cat, dog or wild mammal.
The Skin Fluke is slightly larger than its close relative Dactylogyrus, .4 to .9 mm but genetically is the same - hermaphroditic, both have male and female reproduction organs.
Again for correct identification, and to avoid unnecessary use of chemicals, a mucus scrape is required. Microscope magnification of x200 plus is recommended for positive identification. As this parasite is a livebearer its most identifiable feature is the hook assembly on the embryo in the uterus, this is probably just one of three generations developing inside this parasite. On the Haptor, the posterior end, the two main hooks are surrounded by 16 hooklets, no eyespots are visible.
The Axilla is a shallow depression at the base of the pectoral fin on Koi, this is a common hideaway for most parasites, therefore is always a good area to take your mucus sample. Although some parasites tend to favour specific places, the base of the dorsal fin and tail being two.
During a large infestation of Gyrodactylus the rays of fins and tail may be attacked, left untreated will continue its devastation on reaching the skin. Once the fluke takes a firm hold destruction is rapid.
The lifecycle of the adult Fluke is 12-15 days at 59 F to 68 F (15 C - 20 C). The Adults produce live young, then within one day of birth they themselves produce live young and then one every 5 to 10 days. The young are born fully developed and ready for action as development took place within the grandparent. In a 30 day period a single fluke may give rise to over 2000 more. This parasite is born with everything need to cling to the host, it is usually only spread around the fish population by contact. Given a suitably debilitated fish, more often than not this is brought about initially by poor water quality causing stress, this parasite will breed like aphids.
It is possible to have several generations of Skin Flukes scavenging around in the mucus layer or epithelium of a single fish for cellular denis, blood when it can be obtained or other tasty morsels.
It is important that the Koi keeper learns to recognise the early behavioural changes that parasites can cause. Loss of appetite, lethargy, continuous flashing and flicking and gasping at the surface are all potential signs of a parasitic attack. equally, they can be indications of poor water quality - nitrite for example, is a major skin irritant.
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.
The Skin Fluke is slightly larger than its close relative Dactylogyrus, .4 to .9 mm but genetically is the same - hermaphroditic, both have male and female reproduction organs.
Again for correct identification, and to avoid unnecessary use of chemicals, a mucus scrape is required. Microscope magnification of x200 plus is recommended for positive identification. As this parasite is a livebearer its most identifiable feature is the hook assembly on the embryo in the uterus, this is probably just one of three generations developing inside this parasite. On the Haptor, the posterior end, the two main hooks are surrounded by 16 hooklets, no eyespots are visible.
The Axilla is a shallow depression at the base of the pectoral fin on Koi, this is a common hideaway for most parasites, therefore is always a good area to take your mucus sample. Although some parasites tend to favour specific places, the base of the dorsal fin and tail being two.
During a large infestation of Gyrodactylus the rays of fins and tail may be attacked, left untreated will continue its devastation on reaching the skin. Once the fluke takes a firm hold destruction is rapid.
The lifecycle of the adult Fluke is 12-15 days at 59 F to 68 F (15 C - 20 C). The Adults produce live young, then within one day of birth they themselves produce live young and then one every 5 to 10 days. The young are born fully developed and ready for action as development took place within the grandparent. In a 30 day period a single fluke may give rise to over 2000 more. This parasite is born with everything need to cling to the host, it is usually only spread around the fish population by contact. Given a suitably debilitated fish, more often than not this is brought about initially by poor water quality causing stress, this parasite will breed like aphids.
It is possible to have several generations of Skin Flukes scavenging around in the mucus layer or epithelium of a single fish for cellular denis, blood when it can be obtained or other tasty morsels.
It is important that the Koi keeper learns to recognise the early behavioural changes that parasites can cause. Loss of appetite, lethargy, continuous flashing and flicking and gasping at the surface are all potential signs of a parasitic attack. equally, they can be indications of poor water quality - nitrite for example, is a major skin irritant.
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.