PLEASE STOP USING TTM-IT'S BARBARIC

[MnFish1]

It is unlikely that they stayed on the fish the entire time. Fish can build an immunity to marine Ich. The trophonts cannot feed as effectively and reproduce in much lower numbers but they still follow the same 3 to 7 day time line. Keep in mind that you don't actually see the Ich parasite on the fish, what you are seeing is the mucus excretion on the site where the parasite is. If the parasite isn't feeding effectively, there is no visible excretion on the outside of the fish.
The downside is that if the fish experiences a stressor that weakens its immune system it will start showing symptoms again.

From the University of Florida (great article covering Cryptocaryon)

Fish that survive a Cryptocaryon infection develop immunity, which can prevent significant disease for up to 6 months (Burgess 1992; Burgess and Matthews 1995). However, these survivors may act as carriers and provide a reservoir for future outbreaks (Colorni and Burgess 1997).

 

[Scarybo]

From the University of Florida (great article covering Cryptocaryon)

Fish that survive a Cryptocaryon infection develop immunity, which can prevent significant disease for up to 6 months (Burgess 1992; Burgess and Matthews 1995). However, these survivors may act as carriers and provide a reservoir for future outbreaks (Colorni and Burgess 1997).

This is basically what many hobbyist experience with Ich management. It has been successful for several people on this site. In my experience it is like any parent living with small school age children. Small children seem to be a magnet for colds and flu. When my children were small. I lived with and was exposed to runny noses every year. I never would get sick unless I was stressed from work or just tired. Then it hit me like ebola. Ich management works until it doesnt. Then the results are usually catastrophic to your tank. Just my opinion.

 

[Brew12]

From the University of Florida (great article covering Cryptocaryon)

Fish that survive a Cryptocaryon infection develop immunity, which can prevent significant disease for up to 6 months (Burgess 1992; Burgess and Matthews 1995). However, these survivors may act as carriers and provide a reservoir for future outbreaks (Colorni and Burgess 1997).

I am very familiar with this study. They do act as carriers since low levels of parasites continue to feed on them, drop off, and reproduce. If they were not continuously dropping off the host, reproducing, and re-infecting, there wouldn't be any free swimmers to infect a naive fish introduced into the system yet we know this happens. We also know that if a fish goes around 6 months without exposure to a parasite they will lose their immunity to it. Constant exposure is a key to maintaining immunity.

Edit: This study explains some of the chemical response between the fish and the parasite and includes an explanation on how the parasite is forced to exit early but that they did reproduce and form new theronts. They did not further study the 2nd generation of theronts.
https://www.researchgate.net/publication/273829846_Immune_response_of_fishes_to_ciliates

 

[Outdrsyguy1]

I think your time would be better spent forcing your customers to not put large fish in their medium/small tanks. That would be much more effective at reducing the barbarity of the hobby over starting such an inflammatory thread regarding a commonly accepted practice that doesn't fill our planet with heavy metals and drugs.

Would really appreciate a downvote button on R2R.

 

[MnFish1]

I am very familiar with this study. They do act as carriers since low levels of parasites continue to feed on them, drop off, and reproduce. If they were not continuously dropping off the host, reproducing, and re-infecting, there wouldn't be any free swimmers to infect a naive fish introduced into the system yet we know this happens. We also know that if a fish goes around 6 months without exposure to a parasite they will lose their immunity to it. Constant exposure is a key to maintaining immunity.

Edit: This study explains some of the chemical response between the fish and the parasite and includes an explanation on how the parasite is forced to exit early but that they did reproduce and form new theronts. They did not further study the 2nd generation of theronts.
https://www.researchgate.net/publication/273829846_Immune_response_of_fishes_to_ciliates

Yes - they would have to drop off at some time to reinfect new fish. Im not sure that means that they 'constantly' have to do so - but you're correct, that could be the case. The definition of a 'carrier state' (to me) is different than what you are describing - and it might just be that the summary article chose a poor word to describe what the original study's authors meant. A carrier state is a prolonged period when an organism is living within the host and not causing disease.

 

[Brew12]

Yes - they would have to drop off at some time to reinfect new fish. Im not sure that means that they 'constantly' have to do so - but you're correct, that could be the case. The definition of a 'carrier state' (to me) is different than what you are describing - and it might just be that the summary article chose a poor word to describe what the original study's authors meant. A carrier state is a prolonged period when an organism is living within the host and not causing disease.

I suggest reading the study I linked. You can get the entire study, not just the summary. They document that the Cryptocaryon parasite drops off in as little as an hour and typically less than a day because of the fish immune response. I agree that "carrier state" probably wasn't the best term for what occurs.

 

[Scarybo]

Yes - they would have to drop off at some time to reinfect new fish. Im not sure that means that they 'constantly' have to do so - but you're correct, that could be the case. The definition of a 'carrier state' (to me) is different than what you are describing - and it might just be that the summary article chose a poor word to describe what the original study's authors meant. A carrier state is a prolonged period when an organism is living within the host and not causing disease.

They have to drop off from the fish. Ich cannot reproduce while feeding on the fish. That is the goal of all creatures -reproduction. I believe what the author is talking about is fish can develop a functional immunity. What that immunity (in my understanding) entails is it is better able to resist the stage where the parasite is able to burrow into the skin or gills and feed. If it cannot feed in the swimming stage the parasite dies. This results in lower numbers of the parasite in the tank going through its life cycle. Some still reproduce but small amounts. When a stress event occurs the immunity is reduced (ie. bad diet, work stress, boom sick time)the small numbers or parasites in the tank can take advantage of this window and reproduce in greater numbers. At this point any immunity the fish has developed can be overwhelmed and the fish is ill. The parasite is always present and waiting for any opportunity. In the wild this isnt an issue because the fish isnt captive in a closed environment with a parasite looking to reproduce.

 

[MnFish1]

They have to drop off from the fish. Ich cannot reproduce while feeding on the fish. That is the goal of all creatures -reproduction. I believe what the author is talking about is fish can develop a functional immunity. What that immunity (in my understanding) entails is it is better able to resist the stage where the parasite is able to burrow into the skin or gills and feed. If it cannot feed in the swimming stage the parasite dies. This results in lower numbers of the parasite in the tank going through its life cycle. Some still reproduce but small amounts. When a stress event occurs the immunity is reduced (ie. bad diet, work stress, boom sick time)the small numbers or parasites in the tank can take advantage of this window and reproduce in greater numbers. At this point any immunity the fish has developed can be overwhelmed and the fish is ill. The parasite is always present and waiting for any opportunity. In the wild this isnt an issue because the fish isnt captive in a closed environment with a parasite looking to reproduce.

No actually they develop an immunity. With antibodies and cellular. This is well documented. And if the fish in the tank have complete immunity, the parasite will disappear from the tank over time. If they have partial immunity the parasite will also probably disappear from the tank but more slowly.

And I agree with you to reproduce they have to drop off the fish at some point. The basis for the topic was do they ever not drop off for a longer period leading to a carrier state. Which is what at least a couple sources have suggested.

It has been interesting reading various things my personal conclusion I would never treat fish with copper empirically in a home Qt tank unless the animal showed evidence of sickness during an observation period. Second ttm is not more or less stressful than other qt methods. Third. I will never order fish online

From what I read the immunity does not last only 6 months but it lasts as long as the parasite is in the tank. And there is also some question as to where that 6 month number comes from

 

[Brew12]

From what I read the immunity does not last only 6 months but it lasts as long as the parasite is in the tank. And there is also some question as to where that 6 month number comes from

I don't have time to dig up the study right now but I can later if you want. What the study shows is that if a fish isn't exposed to a parasite for 6 months it will have lost enough of its immunity for the parasite to be a threat again. You are correct that if the parasites are in the system the fish will remain immune.

 

[Scarybo]

No actually they develop an immunity. With antibodies and cellular. This is well documented. And if the fish in the tank have complete immunity, the parasite will disappear from the tank over time. If they have partial immunity the parasite will also probably disappear from the tank but more slowly.

And I agree with you to reproduce they have to drop off the fish at some point. The basis for the topic was do they ever not drop off for a longer period leading to a carrier state. Which is what at least a couple sources have suggested.

It has been interesting reading various things my personal conclusion I would never treat fish with copper empirically in a home Qt tank unless the animal showed evidence of sickness during an observation period. Second ttm is not more or less stressful than other qt methods. Third. I will never order fish online

From what I have read the immunity does not last only 6 months but it lasts as long as the parasite is in the tank. And there is also some question as to where that 6 month number comes from

I dont know if that is truly considered immunity. I would call it "resistance" or an "immune response". The fish needs to be exposed to the parasite constantly. That exposure allows the fish to adapt in several ways to the parasite (greater mucus coat, etc.). This prevents the parasite from feeding and reproducing in sufficient numbers to have a "full"outbreak. However if the fish is not exposed to the parasite for an extended period of time( I have always heard approximately 6 months), the fish loses this adaptation. Also if a new fish that is not immune enters the tank, it can allow the parasite a source to reproduce in sufficient numbers to overwhelm the fish with resistance. I wouldnt really call that immunity. The fish can still develop and succumb to ich with the right conditions.

 

[MnFish1]

I don't have time to dig up the study right now but I can later if you want. What the study shows is that if a fish isn't exposed to a parasite for 6 months it will have lost enough of its immunity for the parasite to be a threat again. You are correct that if the parasites are in the system the fish will remain immune.

I agree with you. And - if the fish hasn't been exposed to the parasite for 6 months, that means the parasite is no longer in the tank. By the way - the reason '6 months' is quoted is because Burgess ended his study of the immune response at 6 months. At 6 months, the 2 'immune' fish developed 11 cysts compared to 272 cysts in the control group.

In his paper he says :
That immunological memory is established in mullet against C.irritans has clearly been demonstrated here with sustained protection of at least six months in the absence of re-exposure to the parasite. (Burgess 1992)

 

[MnFish1]

I dont know if that is truly considered immunity. I would call it "resistance" or an "immune response". The fish needs to be exposed to the parasite constantly. That exposure allows the fish to adapt in several ways to the parasite (greater mucus coat, etc.). This prevents the parasite from feeding and reproducing in sufficient numbers to have a "full"outbreak. However if the fish is not exposed to the parasite for an extended period of time( I have always heard approximately 6 months), the fish loses this adaptation. Also if a new fish that is not immune enters the tank, it can allow the parasite a source to reproduce in sufficient numbers to overwhelm the fish with resistance. I wouldnt really call that immunity. The fish can still develop and succumb to ich with the right conditions.

With all due respect (at least according to the paper) you're incorrect. Read the post above - re Burgess 1992. immune fish at 1.5 months released 0 trophonts and control fish 217, at 3 months immune fish released 0 trophonts and controls 214. At 6 months (the last measurement) immune fish 11 trophonts control 272 (after challenge). These fish were not re-exposed to the parasite during the study - only at the start (ie. there were 5 fish in the 1.5 month group, 5 fish in the 3 month group and 2 fish in the 6 month group. Thus, immune fish do not release trophonts after exposure for 90 days at least. If no trophonts are released in 90 days and there are no non-immune fish in the tank, there will be no more parasite. (From the paper: That immunological memory is established in mullet against C.irritans has clearly been demonstrated here with sustained protection ofat least six months in the absence of re-exposure to the parasite.

Again - Im not saying a person should do anything different with quarantine, etc based on this information. Just found it interesting.

 

[Scarybo]

With all due respect (at least according to the paper) you re incorrect. Read the post above - re Burgess 1992. immune fish at 1.5 months released 0 trophonts and control fish 217, at 3 months immune fish released 0 trophonts and controls 214. At 6 months (the last measurement) immune fish 11 trophonts control 272 (after challenge). These fish were not rexposed to the parasite (ie. there were 5 fish in the 1.5 month group, 5 fish in the 3 month group and 2 fish in the 6 month group. Thus, immune fish do not release trophonts after exposure for 90 days at least. If no trophonts are released in 90 days and there are no non-immune fish in the tank, there will be no more parasite.

Can you post a link to that paper. I would like to read it.

 

[MnFish1]

Can you post a link to that paper. I would like to read it.

https://pearl.plymouth.ac.uk/bitstream/handle/10026.1/2632/PETER JOHN BURGESS.PDF?sequence=1

 

[Scarybo]

With all due respect (at least according to the paper) you're incorrect. Read the post above - re Burgess 1992. immune fish at 1.5 months released 0 trophonts and control fish 217, at 3 months immune fish released 0 trophonts and controls 214. At 6 months (the last measurement) immune fish 11 trophonts control 272 (after challenge). These fish were not re-exposed to the parasite during the study - only at the start (ie. there were 5 fish in the 1.5 month group, 5 fish in the 3 month group and 2 fish in the 6 month group. Thus, immune fish do not release trophonts after exposure for 90 days at least. If no trophonts are released in 90 days and there are no non-immune fish in the tank, there will be no more parasite. (From the paper: That immunological memory is established in mullet against C.irritans has clearly been demonstrated here with sustained protection ofat least six months in the absence of re-exposure to the parasite.

Again - Im not saying a person should do anything different with quarantine, etc based on this information. Just found it interesting.

As i stated the fish can develop an immune response if exposed to the parasite. That immunity is lost if re-exposure is not maintained." For the 2 fish held for 6 months, a relatively lower level of immune protection was apparent, with higher numbers of parasites being sustained following challenge as compared with fish held up to 3 months, and with neither fish showing full protection." Based on the study even at 3 months the fish could be reinfected but it has greater immunity than the 6 month subject.

Are you stating that if a fish develops immunity, that the parasite cannot reproduce and as a result in time the aquarium is ich free. That is not what I took from reading the paper.

 

[Scarybo]

https://pearl.plymouth.ac.uk/bitstream/handle/10026.1/2632/PETER JOHN BURGESS.PDF?sequence=1

Thank you for the link!!

 

[MnFish1]

As i stated the fish can develop an immune response if exposed to the parasite. That immunity is lost if re-exposure is not maintained." For the 2 fish held for 6 months, a relatively lower level of immune protection was apparent, with higher numbers of parasites being sustained following challenge as compared with fish held up to 3 months, and with neither fish showing full protection." Based on the study even at 3 months the fish could be reinfected but it has greater immunity than the 6 month subject.

Are you stating that if a fish develops immunity, that the parasite cannot reproduce and as a result in time the aquarium is ich free. That is not what I took from reading the paper.

Actually I dont think you're reading it correctly. at 1.5 and 3 months (after the exposure to ich) the fish in the immune group had 0 trophonts as compared to >200 in the control group. The next time point checked was at 6 months - where 2 fish (the smallest group) had 11 vs 272 trophonts (suggesting that their immunity is decreasing but not 'gone'. This is also to be expected - just like with a tetanus shot. the immunity gradually decreases until you need a booster. The study actually suggests that there is complete immunity at 1.5 months and 3 months and some reduction by 6 months. And if you added a new fish to the tank with ich, the likelihood is that the 6 month immune fish would survive.

Well - If no trophonts are forming for a 3+ month period (90 days) so no new infections (if all fish are immune). How would you assume that there is still ich in the tank. Isn't the current recommendation 76 days leaving the tank 'fallow'... Having only fish in the tank that are not infected by the parasite should be the same thing.

 

[Scarybo]

Actually I dont think you're reading it correctly. at 1.5 and 3 months (after the exposure to ich) the fish in the immune group had 0 trophonts as compared to >200 in the control group. The next time point checked was at 6 months - where 2 fish (the smallest group) had 11 vs 272 trophonts (suggesting that their immunity is decreasing but not 'gone'. This is also to be expected - just like with a tetanus shot. the immunity gradually decreases until you need a booster. The study actually suggests that there is complete immunity at 1.5 months and 3 months and some reduction by 6 months. And if you added a new fish to the tank with ich, the likelihood is that the 6 month immune fish would survive.

Well - If no trophonts are forming for a 3+ month period (90 days) so no new infections (if all fish are immune). How would you assume that there is still ich in the tank. Isn't the current recommendation 76 days leaving the tank 'fallow'... Having only fish in the tank that are not infected by the parasite should be the same thing.

Not to sound mean , but you are assuming a lot. Science requires testing and proof. No where in the study did it state complete immunity. in fact the author was careful to state that there never was 100% protection. "However, none of the three 1° and 2° exposure levels used here resulted in full protection to challenge in all fish."
The number of throphonts produced dropped on the immune protected fish but even in the best case (the subjects exposed to the highest number of theronts twice before the challenge exposure) only 82% of the fish had no parasites.

Once ich is in an aquarium the only way for it to be removed is to starve it. That means zero fish. If ich has a food source it can survive, the immune fish may show now symptoms but it is still reproducing in low numbers and waiting for an opportunity.

 

[MnFish1]

Not to sound mean , but you are assuming a lot. Science requires testing and proof. No where in the study did it state complete immunity. in fact the author was careful to state that there never was 100% protection. "However, none of the three 1° and 2° exposure levels used here resulted in full protection to challenge in all fish."
The number of throphonts produced dropped on the immune protected fish but even in the best case (the subjects exposed to the highest number of theronts twice before the challenge exposure) only 82% of the fish had no parasites.

Once ich is in an aquarium the only way for it to be removed is to starve it. That means zero fish. If ich has a food source it can survive, the immune fish may show now symptoms but it is still reproducing in low numbers and waiting for an opportunity.

You are reading one part of the experiment - I was reading another. The part you quote above refers to how many fish develop immunity after challenge (not all of them did - but 82% did). We were talking about the 'duration of immune response' which is later in the paper. I agree with you - not every fish that gets ich has 'full immunity' but that wasn't the point. The point was - if they have it, is it 'real immunity - not 'resistance' as you put it, and how long does it last.

The second part of the experiment was they took 12 documented IMMUNE fish and challenged them at 1.5, 3 and 6 months. Table 15 in the paper shows the results . The conclusions (for fish that have immunity)

1. Immunity lasts 'at least 6 months' with no further exposure to the parasite - but probably decreases from there without exposure.
2. The group challenged at 1.5 months had a mean of 2.6 trophonts (the median was 0) compared to control of 262 (suggesting there immunity is developing)
3. The group challenged at 3 months had ZERO trophonts after challenge (assumed to be fully protected)
4. The group challenged at 6 months showed a slight decrease in immunity but still enough to fight off infection.

In the experiment quoted above there was full immunity in the 3 month group. (Quoting from the paper.
Very low parasite levels (%PEI S 0.'2%), indicating a high. degree of sustained immune protection, were observed in fish held for up to 3 months, with full protection being recorded in 60% at 1.5 months and 100% at 3 months.

what that means scientifically, to me, is that in THIS experiment, with this variety of fish, somewhere between 1.5 and 3 months the immune system is fully able to protect the fish (in the absence of repeat exposure), and sometime between 3 months and 6 months that full protection starts to drop. Remembering the key fact - they started with immune fish selected for the experiment.

And by the way I already mentioned one time that I wouldn't change quarantine methods, etc etc for new fish. But if I had a tank with fish that suffered an ich outbreak and survived, I am not sure I would take them all out and treat them with medication after the fact. I would look for any that had even 1 spot and treat them perhaps. I wouldn't necessarily add new fish for several months. Fortunately, I have not had the problem of ich in the tank yet.

 

[MnFish1]

Not to sound mean , but you are assuming a lot. Science requires testing and proof. No where in the study did it state complete immunity. in fact the author was careful to state that there never was 100% protection. "However, none of the three 1° and 2° exposure levels used here resulted in full protection to challenge in all fish."
The number of throphonts produced dropped on the immune protected fish but even in the best case (the subjects exposed to the highest number of theronts twice before the challenge exposure) only 82% of the fish had no parasites.

Once ich is in an aquarium the only way for it to be removed is to starve it. That means zero fish. If ich has a food source it can survive, the immune fish may show now symptoms but it is still reproducing in low numbers and waiting for an opportunity.

I dont want to sound mean either lol. The author stated that there was full protection in 82% of the fish in the first part of the experiment (0 parasites). That means to me that 82 percent of the fish had 'complete immunity'.

The free swimming larvae are able to attach to a host only 5-20% of the time - and they must find a host within 6 hours.
If the parasitic burden drops by 99% in a tank (which is the amount it dropped at 1.5 months, 100% at 3months and 95% at 6 months) compared to controls, how long to you think that that parasite population can be maintained (in a tank of immune fish as documented by the study)

As to the last comment, there are other studies that have shown that ich after 10-11 cycles tends to be less virulent and that assuming one does not add more ich to the tank it will eventually 'die off'. Burgess and Matthews (1994) were attempting to maintain a viable population of C. irritans which could be used in later studies. To maintain the parasite populations, they needed host fish in order for the trophonts to feed and continue the life cycle. Each host fish was only used once in a process of serial transition such that none of the hosts would die or develop an immunity. While the procedure worked very well and enabled them to maintain populations for some time, the viability of the populations decreased with time and none of the 7 isolates they used survived more than 34 cycles, around 10 to 11 months. They suggest this is due to senescence and aging in cell lines is well recognised in Ciliophora.