Ich Cryptocaryon Irritans  

by Beth 

What is it ich?

Ich is a ciliated protozoan called Cryptocaryon irritans. Common names for this parasite in the hobby are: Ick, Ich, white spot disease.

The top two viable choices for treatment of this parasite are copper and hyposalinity. Hyposalinity is the safest treatment option.  Hyposalinity is medication-free so it will not kill-off the bio-filter in your quarantine tank, and fish will not experience the ill-effects of potent medication therapies.  The so-called Reef Safe medications are risky business. They are never very effective and could and frequently do result in negative effects to  your reef ecosystem.

Ich on fins of this Naso Tang

 How does it live?
Ich has a multiple stage life cycle of approximately 2 weeks at tropical aquarium temperatures [77-80 degrees] during which time the parasite undergoes 4 life phases described below:

1.  The trophont stage is seen as the mature parasite attached to the fish, feeding off fish tissue. This has the appearance of salt-like grains often described by hobbyists as white spots or white dots; here is where the common name of the disease, “white-spot disease”, comes from. What the hobbyist is actually seeing with these white dots is a protective covering, or cyst, which the parasite creates over itself as a means of protection.   The parasites’ defense mechanism.   As the parasite feeds and grows, so do these white encasings grow in size.   It is this growth or varying sizes of the trophont that may confuse the hobbyist to think that the infected fish is suffering from some other malady [such as lymphocystis]. The visible distinction between ich, and some other problem, is usually numbers. Left untreated, ich will multiply on the fish and usually cover the body—fins and body alike. Cycle timeframe: approximately 7 days.

2.  The protomonts  stage occurs when the trophont mature after having fed on fish for about a week. At this point, the parasite, engorged and well-fed, detaches its protective cystic covering, leaves the host fish and swims in the water column for several hours until it can find a place in the aquarium to settle. It will then attach itself to a surface in the aquarium:   sand, live rock and, even the surface of rocks where coral are attached, hard-shelled invertebrates, or even the aquarium glass, filters, whatever. Once settled, the cells within the cyst begin dividing to form more parasites [up to several hundred].   Cycle timeframe: several hours.

3.  The tomite  stage, are the products of the parasite reproducing. They become free-swimming in the aquarium as theronts. Cycle timeframe, approx 4 days at 77-80 degrees water temperture.

4.  The theront stage of ich are free-swimming protozoans that must locate a host fish within several hours, or die trying. This is the stage when fish become vulnerable to infection. The infection is transmitted through the water column.

When can ich be killed?
Some ich can be killed while still on the fish with freshwater dips. The operative word here being only “some”. Freshwater dips will not cure ich . At best, it can be used when a fish is so infected with parasitic cysts that serious consequence, such as eminent death, will likely occur if something is not done immediately to alleviate the situation.

Effective treatment, however, can not occur until the parasite has left the fish. Using hyposalinity or copper as a treatment, the parasite is killed when the protozoa is in the water column, in their theront stage.

Why care about when ich can be killed, as long as it is killed?
Because there is a common misconception that the protozoa can be killed as soon as treatment begins, and this is not the case. The hobbyist needs to understand the stages of parasite in order to eradicate it.  As well, not every singular parasite goes through the same stage of the life cycle simultaneously.  Ich is an organism; its lifecycle is not going to be like clockwork in the sense that all parasites in your tank are going to be at the exact same stage a the same time.

What is the most effective treatment that is absolutely safe?
HYPOSALINITY.   Hyposalinity  is Osmotic Shock Therapy [OST].  O.S.T. places the infectors [ich] in an environment in which they cannot hope to survive while the host, (infected fish) can survive. This remedy WILL NOT work in reef systems or systems where invertebrates, live rock, or deep sand beds are a part of the ecosystem.  Hyposalinity (short name is hypo) incorporates lowering the specific gravity of the entire aquarium to 1.009 SG or to 14ppt [parts per thousand] salinity---this SG/salinity being too low for invertebrates, live rock, or live sand where invertebrates reside such as in a deep sand bed (DSB). Marine invertebrates have the same osmotic concentration as the surrounding water and if placed in hyposaline conditions they will mostly die of osmotic shock.   Likewise, this procedure should not be used on sharks/rays, only on bony fish. The procedure, can, however, work very well in strictly fish-only set ups.

The method of lowering salinity/SG is simple: Over the course of 48-hours, salt water in the tank is replaced with fresh reverse osmosis (RO) or distilled (DI) water in several, but small increments until a SG of 1.009/salinity 14 ppt is achieved.   Maintain pH, as pH tends to lower in hypo-saline water; you need to maintain a pH which is safe for marine fish—preferably at the same levels where the fish will permanently reside. The best instruments to use for measuring specific gravity are refractometers or high-quality, lab-grade glass hydrometers. The reason these instruments are recommended is because of their precision and the need to be very precise in attaining therapeutic SG/salinity for the procedure. Never use plastic sing arm type hydrometers. They are basically useless for this procedure, and, really, they are so inaccurate that they should not even be used for routine salt water assessment. As to the beneficial microbes you rely upon to provide natural filtration in your aquaria/QT, NOT TO WORRY! The bacteria colony will survive, the fish will be more than fine; ich, however, will not survive. By lowering the salinity, you will also be lowering the osmotic pressure of the water. The parasites NEED high osmotic pressure to convert saline water into freshwater. All marine animals need freshwater as we do. They just convert it differently, usually via their tissues. Reduce this necessary pressure and the ich will die.   As a higher life form, the fish will do fine with this short-term treatment. Preference for this treatment of ich over copper is based on it being a non-toxic treatment that is very safe to fish.   Hyposalinity has no ill effects on fish during or after treatment, whereas copper is a toxin, and could have enduring negative effects on fish even following a successful treatment.

Maintain the 1.009 SG/14 ppt salinity in the tank for, at the very minimum, 3 weeks AFTER no visible signs of ich are present on your fish. After that time, you can slowly, over the course of several [5-7] days, raise the salinity back to a normal level. Take longer raising the salinity then you did lowering it. If the fish are in a separate treatment tank, leave them there for 5-7 days after returning the salinity to normal levels. If the fish are well after this time, then move them back to the display.

Copper Treatment is highly effective when applied precisely and monitored closely. The drawbacks to copper, however, unlike hyposalinity, is that copper is a toxin---to both parasite, as well as your fish.

In this treatment, the hobbyist will use [best choice] Cupramine which is manufactured by Seachem. You will also need a compatible copper test kit that will “work with” the copper. If you use Cupramine, then also select Seachem’s copper test kit.

You should always set up a hospital tank, never adding copper directly to your display. At all times, maintain therapeutic copper levels in the hospital, using the copper test kit daily. READ THE LABEL of your medication and follow the directions. Like hyposalinity, copper treatment requires precision. Not enough copper, and the treatment is ineffective. Too much copper, and the treatment could be lethal to your fish. Take care, be attentive.  Shortcuts and impatience does not pay off in this hobby.

The treatment course for copper is 3 weeks after you have attained therapeutic levels. Following treatment, you should leave your fish in the hospital tank for an additional week for observation.

What else should I do during treatment?
Continue common sense maintenance practices. That means water changes, water quality tests, etc. In this case, while treating, you will want to perform water changes that match the water in your QT. If your tank is under hyposalinity, then the water you change out, must also be at the same salinity/pH as the water you remove from the tank. Likewise, if you remove copper treated water, then the water you put back into the tank needs to be copper treated as well, at the appropriate therapeutic level.