How to detect if Ich is present?

ThRoewer

New member
I was thinking if there is a way to detect Ich?

I don't mean how to identify it on a fish.
No, the question is how can you test if your fish have a hidden infection due to resistance or partial immunity without dissecting them. Or if there are still theronts present in a fallow system.

Are there any cheap fish that are perfect Ich magnets and never show resistance or even the slightest hint of immunity? It also should be easy to made guaranteed Ich free.

What I'm thinking of is placing a guaranteed clean test fish for 24h into the same tank (or the same water system) with fish suspected to have a low level Ich infection and then keep it in a separate isolated system to see if it will show any symptoms. This has to be repeated daily with a new test fish for at least 2 weeks (72 for a fallow system) or until the first test fish shows symptoms.

What do you think?
How do they do it in Ich research?
 
I was thinking of Black Mollies as test fish. Every time I see them in a saltwater tank they are covered with Ich.
But because they are freshwater fish it should be very easy to get them clean - just transfer them back into freshwater.

Unfortunately I currently don't have the space and resources for such experiments.
But I think it would be good to plan ahead and work out the details
 
This is a great question. I'm in the same boat. My clown had about 7 spots... Looked like ich. Went away (as it should). I plan to QT him and let the tank go fallow.

But in the meantime, I've been asking the same question:

Do I treat him in QT or no? How do I know if there is still ich in his gills that I can't see?

I will be following and posting anything I uncover.
 
I see several issues, but the most important one is that excluding microscopic examination, there is no guaranteed way to determine if ich is present on a fish (e.g. in the gills) or in a tank. "test canary" fish will not cut it.
 
I used to work at a LFS, I have been in hobby for 10 years, I have four tanks.

I can say that 99.99% of tanks have ich. Most fish build immunities. Tanks truly devoid of the parasite will succumb quickly when (not if) it does make it to the system. The fish have zero immunity and will definitely struggle if not all perish.
 
Also, a guaranteed ich fish is a PBT. If you keep them ich free with treatment for a couple months or more, and put them in ANY DT, they will get ich. With good water perams, they will kick it.
 
I used to work at a LFS, I have been in hobby for 10 years, I have four tanks.

I can say that 99.99% of tanks have ich. Most fish build immunities. Tanks truly devoid of the parasite will succumb quickly when (not if) it does make it to the system. The fish have zero immunity and will definitely struggle if not all perish.

I disagree.
 
I see several issues, but the most important one is that excluding microscopic examination, there is no guaranteed way to determine if ich is present on a fish (e.g. in the gills) or in a tank. "test canary" fish will not cut it.

The issues with microscopic examination are
1. you need to kill the fish and cut it apart to do a thorough inspection.
2. even a microscopic examination is not guaranteed to catch every possible infection and you just need to miss one.

So my question is how do they do it in research?
How are they determine whether a fish is clean or infected?
And how do they do it with a tank?
 
Or is it not showing the parasite, which is IMMENSELY more likely.

Based on what evidence? Cryptocaryon's life cycle is well understood; it's not some magical creature that appears out of thin air. If you take the appropriate steps to ensure the parasite never enters the aquarium, it's not going to appear through abiogenesis.
 
Based on what evidence? Cryptocaryon's life cycle is well understood; it's not some magical creature that appears out of thin air. If you take the appropriate steps to ensure the parasite never enters the aquarium, it's not going to appear through abiogenesis.


:lol2::lol2: you must have been waiting quite awhile to put abiogenesis in a post.
 
...
So my question is how do they do it in research?
How are they determine whether a fish is clean or infected?
And how do they do it with a tank?

Step 1 - raise a lot of $
Step 2 - develop/use a PCR assay (detect DNS proteins specific to a single species)

e.g. http://www.eeb.cornell.edu/ecologym...files/Getchell&Bowser'11-PCRfishpathogens.pdf

I assume typically a fish would be killed to take samples, but if you are looking for something like ich, you could sample the floor for cysts/etc.

Anyway, it would be great if this was really helpful! but prob not. Most researchers are likely using a microscope to ID the parasite on the gills.
 
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No, I mean the parasite stays in the tank but doesn't take it over. For instance, ZERO of my fish show any signs of the parasite. Every once in a while (IE after a tank move, or a water peram gets out of whack) it will come back for a few days to a week. Not too strong, but come back.

The fish are immune and the parasite never takes hold and they again fight it off after the root issue is fixed.
 

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