Marine Ich - Myths and Facts

[berkdog]

Thank you Lee! Can you speak to diagnosis of MI a bit more?

From what I read, you describe 3 phases:
Cyst in Aquarium
Free-swimming Parasites
Visible White nodule that is 'pregnant'

Also, similar stages and time-lines (from http://reefkeeping.com/issues/2003-08/sp/index.php):
*trophont (parasite attached to a fish and feeding [sometimes/usually visible during this stage]): 3-7 days
*protomont (parasite leaves fish and travels/crawls around substrate): 2-8 hours, but up to 18 hours
*tomont (parasite attaches to a surface and encysts / reproduces into hundreds of daughter parasites [tomites]): 3-28 days
*theronts (hatched tomites which swim around in search for a fish host): <24 hours

And as you've said, the entire cycle has a minimum near 7 days, and a maximum near 72 days, but usual cycles are 24-60 days.

Given all of these minimum/maximum times, MI can develop to be active in all stages simultaneously I'm assuming, so if it gets bad, the fish can always have visible Ich, right?

But before it's so rampant and visible more often than not, what clues does one look for when diagnosing MI in a quarantine tank situation? Are white substrate dust particles on the fish after a night of sleep (I've read this happened to some people) usually MI even if they only are visible during a few hour window over a week of examination? Should treatment start immediately? Or should monitoring continue until MI is more definitely diagnosed? How could one decide MI is an incorrect diagnosis (if it's not found to be MV, but perhaps nothing or something else)?

Thanks!

[leebca]

Other symtoms include things like breathing rate an flashing, loss of appetite, etc., etc. but because these are the same symptoms of other conditions, only the display of spots have any meaningful means of identifying the parasite.

In the quarantine tank, there should be no substrate, to confusing the parasite with substrate particles is not going to happen.

It's not Marine Ich if the cure, properly administered, doesn't cure the fish. For the most part there are very few pathogens and parasites that appear to be the same. I usually don't recommend taking any curative action when just one spot is seen. At that point, the med and test kit or the refractometer should be at hand and the hobbyist ready to treat should more spots show.

[berkdog]

Thanks for the additional details!

[leebca]

You're welcome.