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 Ichthyophthirius multifilis
The name translates to "fish louse with many children", a title that fits
well, as each parasite may produce over a thousand offspring. Although the
disease is the equivalent of a skin infection, it can easily be fatal to a
fish stressed by poor diet or habitat.
Symptoms:
.Small white spots resembling sand
.Fish scratch against rocks and gravel
.In advanced stages fish become lethargic
.Redness or bloody streaks in advanced stages
Infected fish are covered to various degrees with small white spots. Severe
infestations are easy to spot, but small occurrences often go unnoticed.
However, Ich won't remain unnoticed for long. Like a bad penny, it will be
back with a vengeance.
The adult parasite burrows into the skin of its victim, feeding on blood and
dead epithelial cells. The irritation caused by the burrowing parasite
causes the skin of the fish to swell and produce white cysts seen as a small
spots.
The fish feels as if it's been bitten by a mosquito. It's not unusual to see
infected fish scratching against rocks and gravel in an effort to get
relief.
After several days of feasting, the engorged parasite develops into a
trophozoite, burrows out of the fish and sinks bottom of the pond. Secreting
a soft jellylike substance, it forms a protective membrane inside of which
it divides into hundreds of baby parasites, known as tomites. The hungry
tomites soon leave their home in search of a fresh fish to dine upon.
It is during the free-swimming stage, which lasts a mere three days, that
the parasite is vulnerable to medication. Once it has burrowed into a new
host fish it is safely protected from chemicals in the water.
Treatment:
Transfer the fish to an aerated hospital tank and raise water temperature
to 27 degrees Celcius
.Medicate for 10-14 days or add pond salt at a concentration level of 0.6%.
The entire cycle takes about two weeks from start to finish. Higher temps
will shorten the cycle, while low temps lengthen it. Therefore, raising the
water temp shortens the time it takes for the parasite to reach the stage in
which it is susceptible to medication or salt.
Treatments must be given for a long enough period to assure that all
parasites are gone. Watch carefully for other infections, as secondary
infections often occur where the skin has been damaged by the parasite.
Although nothing kills the parasite once it has checked into its fish
"hotel", several chemicals kill Ich once it has left the fish. Malachite
green, methylene blue, quinine hydrochloride, and mepracrine hydrochloride
are all effective, and are available under several brand names.
The best way to avoid Ich is to quarantine all new fish in a separate tank
for two weeks before moving them to your pond. When quarantine is not
possible, a prophylactic treatment may be used. Either methylene blue or
malachite green given when new fish are introduced and again four days later
will help reduce incidence of infection.
Lernaea
Lernaea or anchor worms are parasites that infect fish and one of the main
problems with them is that they increase the risk of attracting other
diseases. The anchor worms can cause serious damage to a fish and can
eventual kill the fish themselves, but anchor worms are only seldom the
cause of death in fish with anchor worm since the damage weakens the fish
and opens it up for other diseases that end up killing the fish.
Anchor worms are in fact small crustaceans. These crustaceans start out
their life as free swimming and find a fish to burrow their way into. They
burrow themselves too far into the fish to allow for safe removal. When they
have buried themselves into the fish they move themselves into the muscles
where they live for several months while developing. They then make their
way out of the fish, a process that often leaves ugly wounds, and releases
their eggs before dying. The circle will then start over again.
The wound caused by the crustaceans often gets infected which is one of the
main reason this disease can invite so many other diseases to infect the
sick fish. The long time the crustaceans spend in the fish also makes it
hard to know where this disease was introduced from and if it has been
cured. The symptoms of anchor worms include the fish scratching themselves
against everything in the tank and white green threads hanging out with
inflamed centres on the body of the fish.
Treatment:
Anchor worms can be treated by transferred the fish to an aerated hospital
tank and bathing sick fish in a potassium permanganate solution (10mg per
litre) for 20-30 min. Treating the entire pond will color the water and be a
little messy but it is still a god idea since it guarantees that no other
fish are infected and that the disease doesn't return in a few months by
emerging from a fish that is currently showing no signs of infection. If you
decide to treat your entire tank you should add 2 mg potassium permanganate
to every litre of aquarium water in your pond.
Remember that maintaining high water quality, avoiding temperature
fluctuations, and providing a robust diet is the best preventative for Ich
Anchor Worm and most other diseases.
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Ich or White Spot disease
