the ich parasite is everywhere on the fish...even the eyes. The gills are the most delicate tissue with best blood supply and hence easiest and most desirable place for parasiites to attach. You must understand that gas exchange in the the gills happen on a membrane that is a single cell thick. any scarr tissue is a non-working surface of the gills. the fish would simpley cease to exist under the theory you propose. and then you still have to tell us how the parasite is not attaching to the rest of the fish too. is it the same scar tissue theory?
I have already stated on this thread that I will lend some credence to a theory of it is possible to feed your fish a diet which may in turn make the fish undesirable to the ich paratiste ( garlic is a common one) and on that same note may explain how a fish may be able to develop its own immunity via unpleasant or toxic compounds. "also the 11 month ich wears out" studies were done a long time ago!!! be nice to see some more recent data.... and less magic potions!
While I disagree that some scar tissue kills the fish (evolution doesn't tend to allow an animal to exist long term with such as unbelievabley fatal flaw), I TOTALLY agree that my musings are in no way scientific and more than likely just wrong. I'm also not advocating that the scar tissue presents a cure, just noting is as a possible cause for the temporary immunity, and making an assumption that ich thrives in the gills and merely survives given other attachment points. Eventually that scar tissue would lead to a weakened fish that couldn't do much of anything to naturally fight off the parasite, which is when the temporary immunity wears off. Its not scientific, and may or may not have a basis in reality.. I'm not really arguing for it.
I do wonder though why no one has really explored the idea that some fish develop a temporary immunity to something they cannot develop an immunity too. I had hoped someone might chime in with their own theory as far as that was concerned. Ich isn't nearly as mysterious as we seem to make it. Its a parasite, plain and simple. You can't develop an immunity to a parasite. You may be able to defer its affects, or make the host less desirable (as I also agree garlic has some possibility of doing)... but from what I understand, there is no "good" reason proffered for the "temporary immunity effect" Because I'd like to understand, or at least remove my mis-understanding, I posted my ramblings "out loud" I defended the idea in the sense that I'd like to see the subject examined, not as a way to "prove I'm right"
In my opinion, the only way we'll ever find a reef safe cure is to work with the biology of the fish. Most inverts share similar tolerances. Desirable inverts are going to die in the same "range" as non desirable ones, and therefore broadcast type treatments that work in the water column have little to no chance of being successful at limiting only the non desirable. This isn't always the case, there may be something out there fatal only to MI, but with the amount of research that has been done (commercially) in the area, it seems less than likely. The hole (as I see it) in commercial research is that they will always been "held back" by the fact that whatever they choose to introduce to kill the parasite has to be metabolized in such a way as to not be harmful when that fish hits a dinner plate. The imposition of that limit doesn't apply to hobbyists, but hobbyists don't get funded research grants..
Chloroloquine phosphate has shown some success as a food additive. No great success but some. The lack of success could be because actually getting a fish to eat it has been a challenge, or it could be that you can't reach proper "kill" levels without using it in broadcast form. Its just my opinion, but it seems logical to me that something that works with the fish's biology is one of the few things left that has a possibility of being reef safe, and even at that, the delivery system is going to be sketchy.
I don't claim to have answers, but I enjoy the thought process (regardless of how wrong my thought process may be, and I enjoy the feedback on it, when it actually has teeth). I prophylactically treat all my fish as I was bitten by "normal" QT processes, and had to tear a tank down and fallow it. Its a really crappy thing to do to the fish, but it "feels" like a better option for ensuring long term health, and I hope that this process means that I shouldn't need to search for a reef safe cure... but that's all I can do, turn the odds in my favor and hope. I can't prove I don't have ich in my tanks, I can turn the odds in my favor.
I'm not one of those ich folks that is going to jump up and down and scream at someone trying to use husbandry and alternatives to try to cure it either, as long as it is done with an understanding of what we currently "accept" as our knowledge level. The subject doesn't need to be as contentious as it is. We don't need to be so polarized. It results in a scenario where alternatives are not explored or understood, and it stagnates the knowledge pool. There are risks involved with all the scenarios, some greater than others, but summarily rejecting the idea that someone makes a choice you don't agree with is asinine. Science is not just performed in a lab, and while results outside of a lab are harder to quantify and understand, they are no less results. This isn't to say that I think everyone should be experimenting with the lives of their fish. Its to note that if someone chooses a method and understands the consequences of their actions, they need not be lambasted for doing so.
I apologize for writing a "novel" here, but I enjoy a reasoned discussion, and thought making my thoughts clear (regardless of their validity, or the reason-ability if that a word) might help to give context to what I'm typing. It might be all "garbage", I'm not offering it as anything other than MY thoughts.