Using ich to treat ich

[Perpetual Novice]

I know the ich life cycle. I know what will kill it and what won’t. I know how to treat a tank that has ich in it. But I don’t treat the ich in my 30 gallon biocube.

I’ve seen ich at its worst. Infecting almost every fish and multiplying rapidly. But the ich in my tank has never been very aggressive. Many fish have come and gone (moved out to a larger tank not dead) including tangs and every one of them would break out in ich within a week of arriving in the 30 gallon tank. But never to a life threatening extent. they would then fight it off and live comfortably until they move on to my larger display.

I know there are many strains of ich and mine seems to be particularly impotent compared to others I’ve seen and experienced. So I leave it be to help new fish build their temporary immunity rather than treat every new fish with copper.

but this got me thinking. Surely the many fish that were added to the 30 gallon would have brought in other strains of ich over time? The only parasite I treat for is velvet by using a trusted store and doing a brief quarantine since velvet shows symptoms sooner, so new strains of ich would probably be able to make it through my limited quarantine. But I haven’t had any outbreaks or severe symptoms after adding new fish.

I wonder if two strains of ich cannot coexist in one tank. Like in most ecosystems one will outcompete the other. my theory is that my strain of ich is a little like penicillin. It’s more benign and it outcompetes other potentially more harmful parasites and prevents them from spreading.

this is just a theory. But I’m wondering what people think. If it is valid then it stands to reason that one could intentionally culture a strain of ich that is particularly aggressive towards other strains of ich. And particularly benign towards fish. Then you could introduce that strain intentionally to a tank to prevent a dangerous outbreak in the future.

 

[Seanislav]

Biologically, that would be awesome. Rather than stress (and perhaps kill) new fish, let the different strains duke it out, so to speak. Looks good on paper. I have one concern, though...

That would be that if a more aggressive strain of the ich parasite does indeed exist, it likely became more virulent because of its ability to outcompete its adversary by grabbing what it needs to survive more quickly and efficiently...translating to faster and heavier parasitism on its host--fish. The only exception would be if the stronger strain attacked the weaker strain directly. It's not likely, though I'd like to be a part of an experiment in a lab that could test that theory. Great idea, though...that's how science advances.

 

[Perpetual Novice]

Biologically, that would be awesome. Rather than stress (and perhaps kill) new fish, let the different strains duke it out, so to speak. Looks good on paper. I have one concern, though...

That would be that if a more aggressive strain of the ich parasite does indeed exist, it likely became more virulent because of its ability to outcompete its adversary by grabbing what it needs to survive more quickly and efficiently...translating to faster and heavier parasitism on its host--fish. The only exception would be if the stronger strain attacked the weaker strain directly. It's not likely, though I'd like to be a part of an experiment in a lab that could test that theory. Great idea, though...that's how science advances.

yes but if it’s too efficient it will kill the host. If a stain is more potent then it is consuming more resources and is more demanding in terms of the resources it needs to survive. If one strain is programmed to leech enough from a fish to multiply itself 50x and another strain is programmed to multiply 500x then surely the more reproductive strain would need to consume more from its host to afford that sort of growth.

thus the more potent strains which multiply fastest and hit the fish hardest would also be the most sensitive to competition since they require more resources to survive.
Maybe??

 

[ca1ore]

Remember that our tanks are an abnormal environment that multiplies the effect of ich because fish cannot easily escape the parasite. An ich strain that is lethal in the confines of a tank will likely not be in the vastness of the ocean. In all the years I’ve been diving, I’ve not actually seen a fish with ich. I can see no good reason why multiple strains of ich cannot coexist in a closed system as long as there is an adequate supply of hosts. I do agree that different ich strains have different levels of infectious potency. I too have a manageable strain in my tank, though I QT all fish to help to prevent the addition of an additional strain.

It’s been a while since I read up on ich. Presumably it has a sexual cycle as well as a clone cycle? Adding a second strain may well result in a third, consequential strain.

 

[siggy]

@Paul B would agree with you....

 

[Gareth elliott]

There is some truth that strains of a parasite could be used to reduce a parasites wild population.
mosquitos are one such example where they release sterile males into an environment to reduce the offspring produced.
but these are also created in a lab. And this is also the only nominally successful use of this i know of.

Cryptocaryon irritans reproduces asexually which also limits dna transfer between strains. Leading to 2 main drivers of natural selection, number of offspring and survival in the environment. Given the turnover of fish at wholesale and retail businesses, host survival probably has little effect on survivability, of a strain.

 

[ZoWhat]

15yr in the hobby. I've lost a lot of fish to ich. I then 5 yrs old bought this guy

African Cleaner Wrasse..... haven't lost a fish to ich since. My tangs and everyone "line up" for cleaning. It hilarious watch a tang 4 times the size if the Wrasse suspend motionless while being inspected and cleaned



.

 

[ca1ore]

I though that myth had been debunked. Cleaner will remove the dead skin (that’s what the white spot is) but not the actual parasite.

 

[Seanislav]

Hmm...I always thought there was validity in the removal of parasites. I guess I was one of the lucky ones in that I had a cleaner wrasse with a group of tangs, and after an initial infestation of ich immediately after introduction into my system, things cleared and stabilized, which I'd thought the wrasse was helpful in knocking down some. Oh well, it's not like I tested that. Another lesson learned...

 

[ca1ore]

I think it’s been generally debunked. Does not mean, however, that in a tank of adequate size and clientele, cleaner wrasses cannot be helpful. Secondary bacterial infections from ich may be helped by the wrasse even if its not consuming the parasite directly. I have not found the common bluestreak cleaner to be very hard to keep, though they are motivated jumpers.

The ‘trouble’ with ich is that symptoms may present initially, only to subsequently disappear and never reappear. Whatever it was you did at that time then becomes the cause of the cure .... even if it was coincidence. Correlation is not causation. Right after my last ich outbreak, I painted my family room. No reoccurrence of ich. I think we’d all laugh at the suggestion that painting the room cured the ich .... we would, right!

 

[Perpetual Novice]

There is some truth that strains of a parasite could be used to reduce a parasites wild population.
mosquitos are one such example where they release sterile males into an environment to reduce the offspring produced.
but these are also created in a lab. And this is also the only nominally successful use of this i know of.

Cryptocaryon irritans reproduces asexually which also limits dna transfer between strains. Leading to 2 main drivers of natural selection, number of offspring and survival in the environment. Given the turnover of fish at wholesale and retail businesses, host survival probably has little effect on survivability, of a strain.

This feedback has gotten me really excited to learn more than just the basic lifecycle and copper medication techniques I have researched on ich in the past.

I was just reading a paper online about a study conducted on strains of C.irritans that reported the parasite was difficult to study because the population died out after less than a year from "cell degradation" with "the absence of genetic exchange". If I am understanding correctly, the paper is saying that for ich to survive in an aquarium it must be regularly infused with new genetic material from newly introduced compatible parasites. It also outlines how this sort of genetic exchange is feasible within an aquarium environment both on the host fish and in the substrate.

Under this theory, my tank has been kept safe by genes in my ich that make it more impotent. When new ich arrives, it "breeds" with the ich I have to eventually produce a new homogeneous population with a slightly different genetic code. The genes from my tanks ich that keep my fish safe must be dominant or each new hybrid would potentially adopt a more infectious set of genes from an incoming strain. The breeding keeps the genes from degrading so my tank strain doesn't die out but the dominant genes that blunt the parasites affect on my fish are passed on each time.


I like the mosquito analogy. Because what I learned from this paper is that ich is reproducing "sexually" to some degree in our tanks. If it weren't, then it would die out from the same process that causes any animal to age and die, as its cells divide a finite number of times. So if ich is breeding and sharing genes in our tank, then, like the mosquitos, all we have to do is introduce a gene that will make the ich less harmful and infectious (although in this case we don't try to make the offspring sterile and instead try to keep the genes alive in future populations).

I could imagine going and buying a bottle of "weak ich" at my LFS and adding it to my tank. The ich would be just potent enough to feed on fish and reproduce but not threaten their health. Then any time a fish enters the tank with a lethal strain, it breeds with the "weak ich" already living in the tank and adopts the "weak" genes (assuming they're dominant, which they would have to be for this to work). The only bit of maintenance this system would require is that you would need to make sure to occasionally introduce new strains to keep your ich population alive ahaha.

hows that crazy idea? Ive got a degree in chemical engineering not biology.

 

[Gareth elliott]

@Perpetual Novice
Its an interesting theory it dies from lack of genetic input. Though not sure you could rule out eventual immunity occurring in the fish also playing a role. There will always be some genetic variation even in asexual reproduction. There are i think 6 major ways that species reproduce asexually, if I remember correctly anyway. Parthenogenesis is common in some aquatic invertebrates.(i have no idea the method ich uses tbh)
And with any pathogenic species cross dna transfer from either bacteria or the host can not be discounted.

 

[sp1187]

Right after my last ich outbreak, I painted my facility room. No reoccurrence of ich. I think we’d all laugh at the suggestion that painting the room cured the ich .... we would, right!

does the color matter?

 

[saltyhog]

I know the ich life cycle. I know what will kill it and what won’t. I know how to treat a tank that has ich in it. But I don’t treat the ich in my 30 gallon biocube.

I’ve seen ich at its worst. Infecting almost every fish and multiplying rapidly. But the ich in my tank has never been very aggressive. Many fish have come and gone (moved out to a larger tank not dead) including tangs and every one of them would break out in ich within a week of arriving in the 30 gallon tank. But never to a life threatening extent. they would then fight it off and live comfortably until they move on to my larger display.

I know there are many strains of ich and mine seems to be particularly impotent compared to others I’ve seen and experienced. So I leave it be to help new fish build their temporary immunity rather than treat every new fish with copper.

but this got me thinking. Surely the many fish that were added to the 30 gallon would have brought in other strains of ich over time? The only parasite I treat for is velvet by using a trusted store and doing a brief quarantine since velvet shows symptoms sooner, so new strains of ich would probably be able to make it through my limited quarantine. But I haven’t had any outbreaks or severe symptoms after adding new fish.

I wonder if two strains of ich cannot coexist in one tank. Like in most ecosystems one will outcompete the other. my theory is that my strain of ich is a little like penicillin. It’s more benign and it outcompetes other potentially more harmful parasites and prevents them from spreading.

this is just a theory. But I’m wondering what people think. If it is valid then it stands to reason that one could intentionally culture a strain of ich that is particularly aggressive towards other strains of ich. And particularly benign towards fish. Then you could introduce that strain intentionally to a tank to prevent a dangerous outbreak in the future.

Interesting premise.....much like a live strain vaccine used in medicine. There have been instances where live strain vaccines have regained their ability to cause disease however. Short term success doesn't guarantee long term success.

Can you describe your quarantine procedure? How are you treating for velvet?

 

[Perpetual Novice]

@Perpetual Novice
Its an interesting theory it dies from lack of genetic input. Though not sure you could rule out eventual immunity occurring in the fish also playing a role. There will always be some genetic variation even in asexual reproduction. There are i think 6 major ways that species reproduce asexually, if I remember correctly anyway. Parthenogenesis is common in some aquatic invertebrates.(i have no idea the method ich uses tbh)
And with any pathogenic species cross dna transfer from either bacteria or the host can not be discounted.

Yeah, the paper is pretty clear on each of their ten unique samples dying out before the 34th asexual reproductive cycle while in genetic isolation and it proposes that the cause is very likely cell degradation. The paper does not give an actual method for genetic exchange, but instead points out the points in its lifecycle where it has been observed to come into contact with partners long enough for genes to potentially be exchanged.

****
unrelated to my original idea, I was reading on about how they found the parasite was photosensitive and tuned to day/night cycles. The paper explains that, after feeding, the parasite waits until dark to release from its host and fall to the substrate. this is both to avoid predation from planktivores. the theronts also only hatch in the dark to make it easier for the newly hatched offspring to infect fish since most fish are diurnal and will be sleeping near the substrate at night. Here is what I found particularly interesting. The paper notes that this is necessary for effective infection of a new host because a free-swimming fish away from the substrate and in a high flow environment is very difficult to latch onto. "it is evident that a large proportion of theronts must locate and invade a host in the absence of light, if they are to survive". That quote must be referring to a wild environment and in a home aquarium, the theronts would be much more abundant so infection is inevitable.

Even still, I would extrapolate a plan in case of a future outbreak where I would leave the lights on, or cycle short naps instead of day-night cycles, as well as jack up the flow in my tank, to reduce the parasites infective capacity.

 

[Perpetual Novice]

Interesting premise.....much like a live strain vaccine used in medicine. There have been instances where live strain vaccines have regained their ability to cause disease however. Short term success doesn't guarantee long term success.

Can you describe your quarantine procedure? How are you treating for velvet?

in terms of quarantining, I just leave the fish in my quarantine tank for 1-2 weeks. mostly I really trust my lfs. I know who their suppliers are and I like their quarantining procedures.

Mostly though I know how long velvet can remain attached to a fish. My lfs always runs a precise and potent dose of copper in their tanks. That means that, even if a fish arrives with ich or velvet, or if there are free-swimming parasites in the water the fish arrives in, the parasites cannot infect new fish after one life cycle. in the store any incoming parasites feed, fall off, encyst, but then die upon hatching. So no healthy fish can be infected by incoming parasites that fall off a new infected fish. most of my protection comes from only buying fish that have been at the store at least 2 weeks (long enough to be certain any velvet they might have arrived with has fallen off. The only possible velvet could survive its way to my tank is if it had just hatched when my fish was collected and was not killed by the copper before my fish was released into its new copper-free environment. Since the free-swimming stage is the only life stage that could possibly escape the store, velvet would immediately become present on the fish i bring home because its very next life stage is to infect a fish. so i dont need to wait and see if any velvet was lying dormant since any incoming parasites could not be in a dormant life stage. So yeah, confirm the arrival date of the purchase, and give it a week of observation.

 

[ca1ore]

I was just reading a paper online about a study conducted on strains of C.irritans that reported the parasite was difficult to study because the population died out after less than a year from "cell degradation" with "the absence of genetic exchange". If I am understanding correctly, the paper is saying that for ich to survive in an aquarium it must be regularly infused with new genetic material from newly introduced compatible parasites. It also outlines how this sort of genetic exchange is feasible within an aquarium environment both on the host fish and in the substrate.

My own personal experience is that it is not true. The ich strain in my system still persists after 6 years. Now, is it possible additional genetic strains have been introduced - yes, but since I do a pretty rigorous QT on all new fish, I think it's less likely. Only way to know for sure is to not add any new fish for a year and see if it dies out.