Can ich lie dormant?

[jjohnwm]

You sure? I've always been told it was a fungus, and I've always treated with antifungals. If so I've been lied to, and I have shamefully made the mistake of telling people the same.

Don't believe me, I'm just another anonymous internet entity. I don't completely trust anything on the net either.

Not sure how to prove it to you, but...yeah, you've been lied to. Ich was a parasite that we studied in detail when I was in university; I remember it vividly because my Invertebrate Zoology prof and I were the only two people in the class who spoke English, so I got a fair bit of one-on-one instruction. Everybody else just put their tape recorder...yes, tape recorder...on the desk and presumably had somebody translate for them later.

But...it's not a fungus.

 

[whomikebrown89]

From my experience, 2 weeks no host is usually enough for freshwater ich. But if in QT I will "treat" for 4 weeks.

 

[Cal Amari]

Well if we're throwing myths out here to see what might be true, I was told by another customer at the lfs, not an employee even, that ich is present in most water sources, even in dormant cysts, which duanes could probably validate or negate. If this is true, like already said, it's in the water just waiting until a hosts immune system is weakened enough by stress or other disease to gain a foothold. It could get in from any water change unless you wre using distilled or R?O water or something.

 

[FINWIN]

Thanks for the info everyone! I was asking this because I'm going to start a research project on ich dormancy which I'm really excited about

post up what you conclude!

 

[FINWIN]

It's on...

 

[jjohnwm]

Here's the part that puzzles me: Let's say that there is some percentage of Ich parasites that can remain in a dormant state for weeks, months, years, whatever. In that state, they are non-infective; they must be released from the cysts, at which point they are free-swimming and must find hosts within a short time. That's the stage of the life cycle which we can kill; when they're encysted, or later when they are embedded in the host, they are pretty much untouchable. We need to kill that vulnerable free-swimming stage. This is why treatments must continue for at least a couple weeks, so that any parasites that are in another stage of the life-cycle eventually become vulnerable to treatments.

Now the "common wisdom" that I mentioned earlier always preached that an infestation of Ich results from stressing the fish, often by a sudden drop in water temperature; just from experience, this seemed to be believable. Okay, so...the fish are stressed and susceptible...but what caused the encysted, dormant parasites to become released and free-swimming, and thus infective? Merely stressing the fish doesn't make the encysted parasites able to latch onto them; they must escape their cysts first. How, when and why do they do that? What makes a dormant parasite suddenly re-animate and go on the hunt for a host...at just the exact time that the host is stressed and susceptible? Does that same temperature drop "wake them up"?

Or, is the parasite virulent enough in the infective free-swimming stage that it's going to infect any fish, stressed or not? If that's the case, we're back to that same question, i.e. what caused them to break out of their cysts?

If there is simply some random time at which the cysts break open...why then do some tanks never get an Ich infestation? I've dealt with Ich many times over the years...it's more of an inconvenience than a deadly threat...but I've also had tanks that have run for years...in one case for almost 15 years...and never had a white spot during that entire time? Just luck of the draw? Or is Ich not that universally distributed amongst all water bodies and fishtanks, as we are often told?

Too many questions; I hope the OP is about to answer all of them!

 

[jjohnwm]

Well if we're throwing myths out here to see what might be true, I was told by another customer at the lfs...

...who heard it from a buddy...who read it on the internet, on the "Look at my new aquarium!" picture posted by some kid on TikTok...who knows another kid whose father is friends with an old-timer who read it in an issue of TFH magazine that he found while cleaning out his attic...

Talking to other customers at the LFS may be a source of priceless nuggets of information, difficult to obtain anywhere else, which can alter the course of your fish-keeping hobby for the better...

...or can just as easily...or even more easily!...feed you absolute nonsense with no basis in fact or logic.

Distinguishing the difference can be a challenge.

 

[Cal Amari]

Agreed, but with this particular questionable nugget it changes nothing in practice, just theory of understanding how it got into the tank. I'm old enough to be skeptical of any free advice.

 

[SalviniCichlidFan]

Wow these are all great responses and now I have a lot more questions than I started off with! I think this post alone can create 10+ different research projects on ick especially with what jjohnwm posted. I might make this a long-term project now! I'll keep you guys updated, keep giving these great ideas and suggestions!