Home Articles Veterinary medicine Articles Ich
Ich (pronounced ick) is a common parasitic
disease that commonly affects all fish in aquaria. In fresh
water systems, it is due to the presence of the single-celled
parasite Ichthyophthirius multifilis. In marine water systems,
it is due to the presence of the single-celled parasite Cryptocaryon
The lifecycle of the parasite is similar for
both marine and fresh water systems. The adult parasites dig
their way into any exposed part of the fish or under its scales,
more commonly in its gill plates. It then consumes the fish's
skin cells until it has grown into a trophozoite, at which point
it falls off the fish and lands on the bottom of the tank. It
covers itself (tomonts) with a jelly and divides into several
thousand new free-swimming larvae (theronts). These larvae swim
around until they find a new fish to infect, at which point
the process repeats.
Ich is fairly easy to treat in the freshwater
aquarium and usually forms during the introduction of new fish
or times of stress. The most common recommendation is Malachite
green, a mild antifungal.
Ich can be extremely difficult to treat in
marine aquaria due to the presense of other creatures such as
invertabrates or corals which will not survive standard ich
treatements. There are two known methods to treat marine ich,
one is using a form of copper and the other is using hyposalinity.
Ideally, you want to quaranteen your ich infested fish in a
hospital tank and treat them with one of the suggested treatements.
Even after treatment you will still have an invested display
tank, which needs to run fallow for 6-9 weeks (the longer the
better). After which time the tomonts will have hatched into
the theronts stage and have between 24-48 hours to find a host