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Lernaea - Anchor
worm is a common parasite on our Koi which is clearly visible
to the naked eye and can reach 10 to 12mm. The parasite burrows its head
into the Koi's tissue, under a scale and only the body and tail are normally
visible. Lernaea lay eggs which can lay undetected in the pond and can
hatch when conditions and water temperatures are right. |
| Treatment is by manual removal of the parasite with tweezers under
anesthetic, ensuring that the whole parasite is removed. To be sure of
complete removal, dip a cotton bud in strong potassium permanganate solution
and dab the worm with this solution whereupon it will release its grip
immediately. Pond treatments include Dimilin or Paradex |
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Dactylogyrus -
The Gill Fluke. Gill and Skin flukes are two of the family of monogenetic trematode
genera, all of which are characterized by the large grappling hooks which
are used to attach themselves to their victims.
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| Flukes are another common parasite affecting our Koi are both egg
layers and live bearers. They range from 0.05 to 3.00mm long and there are
actually a huge number of species in the genus. Affected Koi often
exhibit classic signs of irritation and flash or rub themselves against
objects in the pond in an attempt to rid themselves of their attackers. |
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Gyrodactylus - The Skin Fluke.
Koi suffering from infestations of gill flukes may suffer respiratory
problems as the flukes begin to damage the delicate gill tissues. Secondary
bacterial infection often occurs in Koi left suffering from these parasites,
due to the physical damage caused by the anchors.
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| Chemical control of both types of fluke can be achieved with Chloramine
T, Malachite Green Formalin and Masoten, or Potassium Permanganate. In
order to kill all generations, repeat treatments may be necessary, the
frequency being dependent on temperature and chemical used. |
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Argulus - The
Fish Louse It is said that this parasite can be commonly introduced into our
Koi
ponds by frogs and toads. It is however easy to detect with the naked eye
especially against the background of fins and white skin of affected Koi.
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| Size varies from between 1mm and 5mm. Attaching
themselves to the Koi by
suckers which damages the skin, they also inject a poison into the body of
the Koi which causes inflammation, bleeding and potentially secondary
bacterial infection.
Chemical treatments recommended to eradicate these parasites are either
Masoten, Dimilin or Paradex.
Repeat treatments may be necessary to ensure that all generations of the
parasite are killed.
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Chilodonella is classed as the most dangerous of the Protozoan parasites
and can cause mass fatalities especially in overstocked ponds and aquaria. It is between 40-60 microns in diameter and can be easily identified on a
microscope slide using 100 x magnification.
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| Affected Koi may show classic signs of flashing and rubbing, may hold
their fins clamped against their body and appear listless. They will also
hang at the pond surface and gasp for air in severe infestations. Recommended treatments include Malachite Green and Formalin, Potassium
Permanganate or Salt baths at 3% ( 4 and one half oz. per gallon ) |
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Costia is a minute Flagellate with 3-4 flagella. It affects both the skin
and gills of Koi, and reproduces itself by binary fission. Infestations of
this parasite can appear very rapidly indeed, and Koi suffering infestations
exhibit the classic symptoms of lethargy, clamped fins, rubbing and flashing
and the skin can take on a grey white opaqueness. |
| Costia normally only affects fish that have already been debilitated by
some other cause, and can often be seen on Koi as a secondary parasite. A high magnification must be used to view these parasites (300 x) and
staining is recommended for positive identification. Recommended treatments include Potassium Permanganate,
Acriflavine and
strong salt baths of 3% ( 4 and one half oz. per gallon ) |
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Trichodina is one of the easiest protozoan parasites to detect under the
microscope as it is almost perfectly round with hundreds of hooks which
resemble cilia found its periphery and it constantly rotates as it moves
through the mucus, causing tissues damage. It attacks both skin and gill tissues of our
Koi, and can often cause
more damage to gills than realized. |
| Classed as a warm water parasite, it can survive for some time without a
host. It causes vegetation of the skin giving rise to a grey white opaque
appearance on the body of infected Koi which exhibit the classic symptoms of
flashing, rubbing and lethargy.
A magnification of 100 to 200 x is required to view this parasite. Recommended treatments are Potassium Permanganate.
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White spot
swarmers
Chemical treatments have to be long lasting and repeated several times to
rid the fish population of these parasites. Recommended treatments are
Acriflavine, Malachite Green and Formalin, and prolonged use of salt at one
half oz per gallon.
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| Chemical treatments should be repeated at least twice to ensure complete
eradication. |
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Ichthyophthirius multifilis (Ich) -
White spot , one of the ciliates, showing the classic horseshoe shape
macronucleus is classed as a large protozoa, which can be detected by the
naked eye on infected fish by the appearance of hundreds of tiny white
spots where the parasite has bored through the skin of the host. |
| The adult parasite drops off the host, surrounds itself
with a capsule and fixes itself to a plant or rock. Inside the capsule the
parasite divides and multiplies and eventually 250 - 1000 tiny 'swarmers' are released and these then swim off in search of a new
host. The swarmers typically attack the dorsal and caudal fins of Koi,
although gills and body are also affected. The swarmers burrow through the
surface of the skin and so the parasite resides in the body and not on the
body of infected fish. The complex nature of the life cycle of white spot can render it
difficult to treat as it is only the free swimming swarmers that can be
killed with chemical treatments. Once the swarmers attach themselves to our
Koi, until they detach as adult parasites can take between 4 days at 27 deg
C (80 deg F) and up to 4 to 5 weeks at 10 deg C (50 deg F). The parasite
becomes encapsulated in only one hour after leaving the host. Newly
produced swarmers can however only live without a host for up to 55 hours
maximum, so by simply removing Koi from a pond for three days, it can be
cleared of the parasite completely. |
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