Ichthyophthirius multifiliis- Please respond to poll with your experience

[aldiaz33]

In regards to Ichthyophthirius multifiliis (AKA- Ich or Ick) there seem to be two schools of thought:

1. Ich is always present in the water column and presents itself on weakened or stressed fish.

2. Ich is not always present and must be introduced to your tank in order for your fish to be infested.

I'm curious to hear what your experience has been.

Please vote and share your thoughts/experience. *



* If you vote #1 (that it's always present), please be able to say with certainty that in the month prior to the outbreak there was no possible way for the parasite to be introduced into your water column. Some methods of contamination include, a new fish added to the tank, sharing a net with a contaminated tank, adding a plant from a contaminated tank, sharing filter media from a contaminated tank, etc.

I am very interested in hearing from people who say they have had an Ich outbreak on a tank that has been set up for quite a while that has had zero possibility of an external introduction of Ich.

 

[ecoli73]

Introduced.

I do however think sometimes if ich treatment was not thorough, latent infections can hang around for a long time.

My experience also that when some fish gets ich, it is not automatic that all fish will come down with them. A week or so prior to Xmas, a group of newly acquired clown loaches came down with ich. I did not discover it until the infection was quite advanced(they were hiding in the rocks until on their last legs)...I lost 4 out of 5 infected. But I had 35+ other clowns in my tank and none of my older ones got it.

I copper bombed the tank of course but the degree of ich that was on those infected indicated that they had gone multiple cycles in the tank prior to treatment; and not once I see spots or flashing on my other fish, including other clowns.

 

[aldiaz33]

I agree...I tend to think they have to be introduced too, but I have seen several people say they have had outbreaks in established tanks with no possibility of contamination, so I'm not so sure.

I've had the same issue with you as CLs...I think everything is ok because they are usually shy at first in a new tank, then they come out of hiding and Bam!....Surprise!... they look like they've been rolling in salt granules, totally covered.

I had a group of loaches in quarantine for 3 weeks and they looked perfectly healthy; no signs of Ich whatsoever. The day after I added them to my display tank (after the 3 week quarantine) they were covered in spots (trophonts).

From what I've read, the Trophonts will typically attack the fishes gills where we can't see them. When you see it appear on the fishes body, it's already progressed. I think that's what happened with my CLs...I should have QTed for a full month.

In my experience, bottom dwellers always get it the worst, which makes sense since apparently the tomites emerge from the substrate (and in the case of bottom dwellers) don't have to swim very far to find a host.

 

[duanes]

All it takes is one dormant cyst to be brought into a tank, it can be brought in on a plant, a rock, a piece of waterlogged wood, or obviously a fish. And "one" would not be obvious at first on a fish, it usually isn't obvious until there are many.
There is also a theory that dormant cysts can remain viable frozen, or dry.
In nature, it is very hard for ich to evolve into epidemic proportions, because fish are not as concentrated as they are in a small tank.
There is also a theory that fish exposed, and "cured" build up a sort of immunity to a point, but can be overwhelmed if populations of ich become too high.

 

[Humilus]

I would have to side with those that say they must be introduced, although it can definitely remain inactive but present for quite a long time. I have had local native fishes of various species (wild caught) for years who had never caught ich, despite the heightened stress levels associated with capture and acclimation. I was very proud of the fact during the time!

One of my friends then gifted me a trio of Petsmart-bought guppies for my birthday last year. They did surprisingly well in their unheated aquarium, and lived for about half a year (one day I had the bright idea of placing a young Green Sunfish from a different tank in their aquarium while I was cleaning his aquarium out...). Now, some of the cyprinids in the guppies' former home will catch ich if stressed out by a major plant rearrangement, although the darters and a small Orangespotted Sunfish don't seem to. The darters and the sunny will scratch, but they stop doing so after a few days and never get white spots.

This leads me to wonder: how many other species are resistant to ich? Are there any that are immune?

 

[aldiaz33]

Interesting stuff.

Bump for a larger data set. Please share your experience, especially if you had a random outbreak in a well established tank.