Ich question

[recess62]

so the widely agreed length of time to leave a dt fallow to rid a tank with ich is about 75 days. The life cycle of the parasite requires a host organism. It is also believed that fish that are stressed get infected by the parasite and continue the life cycle and produces white spots.

So here is my question. If you inadvetantly introduce the parasite into a tank of healthy fish and you never have a fish show any signs of infection, would the life cycle get interrupted In the tank and eventually become ich free. Can fish be asymptotic hosts?

 

[Humblefish]

So here is my question. If you inadvetantly introduce the parasite into a tank of healthy fish and you never have a fish show any signs of infection, would the life cycle get interrupted In the tank and eventually become ich free. Can fish be asymptotic hosts?

There is some evidence that a fish's natural immune system can develop resistance/immunity to external parasites such as ich. But it's not well understood exactly under what conditions this happens and for how long. It does seem like a small percentage of fish are capable of developing immunity to velvet and possibly even ich for a period of time. I read somewhere this usually wears off after 6 months, but during this time the fish are still carriers.

Another thing to consider is ich is a relatively mild parasite - so long as its numbers are kept it check. Most fish can live with a slight infestation. When ich's numbers are few, the trophonts will often only be found in the gills, and unless you are paying close attention for behavioral symptoms you may not even notice that the fish has ich. The problem is sometimes the situation can spiral out of control, a "stressor event" occurs (if you want to call it that), and most of your fish can succumb to the parasite if their immune system gets lowered and/or the number of parasites increases exponentially.