advice needed

[bjolly]

please help! I had an ick outbreak in my tank recently. I do quarantine but back when I started in the hobby I didn't. I can only assume the ick somehow lingered in the tank all this time. I tried to catch the fish to treat them, and only succeeded in getting one, who died in the treatment tank the next day.

I have 5 fish still in my tank and they have been looking healthy and normal again for several weeks. 3 of them definitely had the disease but have recovered, the other 2 didn't get it as far as I can tell.

do I need to get all the fish out and treat them to rid the tank of ick? catching them would be a nightmare but I will find a way if it's the only way to avoid going through this again.

I posted about this earlier and someone said they doubted it was ick since the 3 fish had recovered and were still fine weeks later. They advised not doing anything just yet.

Can anyone advise what I should do? take everything apart and catch the fish? leave them in there and hope for the best?

 

[SAT]

That experience is fairly common: when Ich is introduced it kills the weakest or least resistant fish, some get it but their immune system kicks in before they die, and some are already resistant. It is likely that if you do nothing the fish will continue to survive and you will have Ich resident in the tank for an extended period, basically waiting for "fresh meat" or for some event that lowers the fishes resistance.

So, one option is to do nothing. Over a period of a year or two the Ich will slowly become less viable and die out. That assumes you don't introduce any fresh parasites in that period.

The second option is to try to eradicate them. Assuming you don't want to wipe out your reef, that involves catching the fish, placing them into a treatment tank, treating the fish for Ich, and then waiting 6-8 weeks for the display tank to be clear.

It's somewhat unlikely, by the way, that Ich would have remained undetected in the tank for 2+ years and then suddenly woke up and started killing fish. It's much more plausible that it was inadvertently introduced recently, either on a fish that didn't show through quarantine (it's possible, but somewhat unlikely if you quarantined for more than 4 weeks) or on some other wet object such as a piece of coral or live rock.

 

[leebca]

Attack by Marine Ich (Cryptocaryon irritans) is not a matter of fish resistance, Stuart. If the fish is immune, it's immune. If the fish is resistant, like mandarins, it is resistant because of its physiology or physical characteristic(s). But whether the fish is sick, healthy, or in anyway compromised by a poor environment does not determine whether or not the fish will get Marine Ich (MI). This is not a correct concept:

. . .or for some event that lowers the fishes resistance

I also don't know where you found this to be true:

Over a period of a year or two the Ich will slowly become less viable and die out.

I accidently came across a phenomena when trying to maintain a viable stock of disease organisms in my 1970's study of MI. I found that in about 10 months, the disease wasn't infecting. Dr. Burgess & Matthews in 1994 found that after about 34 cycles (10 to 11 months), the disease doesn't infect due to senescence and aging in cell lines, which is a well recognized feature in Ciliophora (the family of diseases that Marine Ich is in). It takes less than one year for the disease to lose its ability to infect/cause harm.

 

[Rondelet]

Lee,

Interesting observations. I know I've asked this before, but can you post the Burgess & Mattews (1994) reference if you have it handy.

Having said that, I do believe resistance and the status of the immune system play a role in the short term. I have a Yellowtail Angel that had ich in quarantine. I treated the fish using a multi-pronged approach (which did not include hypo or copper) and the clinical signs eventually cleared up after about 3 weeks. I then held the fish in Q for another 6+ weeks (I would have to check my records - it may have been a little longer) during which there were no signs of ich or other disease. I then moved the YA to my main display wherein it was terrorised by a much larger Regal Angel (the resident and undisputed boss of the tank). Not long after white spots began to show up and I was at a cross roads as the YA was starting look beat up and was doing poorly - but holding its ground. I was worried about both it and the other inhabitants of the tanks, and in particular the RA (there is also a Regal Tang in there). But to remove any of the fish would mean tearing the entire tank down. So to buy time, I treated with metronidazole in the feed, added a second cleaner shrimp and waited. At the same time aggression from the RA abated as all the fish settled down, and in particular the RA's acceptance of the YA. I discontinued the metro (in the feed after about a month). The spots appeared to clear up and the fish started to do a lot better. Currently (cf a month later) all the fish are doing fine, although the RA still takes the odd shot at the YA as he is something of a bully. Interestingly, not long after I had a mild ammonia spike in my tank that nearly did in a sponge and leather coral due to an issue with a mechanical filter I was using. I quickly fixed the problem and moved the sponge and leather coral to another thank (where they are now on the mend). At no time did Cryp show up on any of my fish.

Kind of long winded, but the short of it is I do believe Cryp can be managed to a certain degree, that immunity and stress play a role, but also that over time the parasite's infectivity will attenuate as you've observed. So my advice to the original poster would be to wait and see. Under the right conditions (good water quality and nutrition) fish can live with and fight off Cryp infections. I also think cleaner shrimp, if compatible with the fish you have, are very cost effective for managing fish health in your tank.

 

[leebca]

The reference (again)
Burgess P.J. and Matthews R.A. 1994. A standardized method for the in vivo maintenance of Cryptocaryon irritans (Ciliophora) using the grey mullet Chelon labrosus as an experimental host. J Parasitol 80]/b]:288-292.

Rondelet,

You seem to miss an important point. Mine are not observations at all. They are based upon scientific fact.

There are still many parameters you haven't taken into account. The treatment you think you performed could have crippled Marine Ich and not destroyed it. The organism would not be able to infect or get to the 'mature Trophont' stage (the only visible stage to the naked eye).

The thing is, you have some observations, but what they mean scientifically is totally unknown. We can guess for ages on it and still not have it right. Beside the above scenario there are others known in parasitic microbiology which affect the viable nature of an organism as well as a multitude of factors that affect the susceptibility of the host. The conclusion you draw from what little has been observed is possible, but highly unlikely. It doesn't fit what is currently known.

I don't make the 'rules.' But I know there are many more of the 'rules' then you or I are aware of. The statements made by Stuart don't fit the current scientific evidence. But I'm open to learn more.

 

[Rondelet]

Lee,

Many thanks for the ref - I'll try too not to misplace it this time! :spin2:

I agree that 'observations' such as I've provided are very limited. However, clinical observations can be a very valuable tool in the management of disease. I am all for testing null hypothesises with respect to treatments/practices that may or may not work for managing disease. In my case, however, control groups and replicates would have been very expensive. Yellowtail Angels are not cheap!

Where I have trouble is that, if I understand you correctly, you seem to be suggesting that immune function is all or none. That is, 'immunity' is either there or not there. I donââ"šÂ¬Ã¢"žÂ¢t agree. To given an illustrative example (off the top of my head): why is that those who are allergic to peanuts and are exposed to peanuts break out in hives in some instances - but in other instances have a full anaphylactic reaction? Similarly, in fish, often minor exposure to pathogens does not cause clinical pathology, but if you expose the fish to enough pathogens (that is, increase the challenge burden significantly) then the fish succumbs and dies? Further, if you vaccine fish, response to vaccination (as measure, for example, by antibodies titres) you will find a range within the vaccinated population. From this we know that certain titres are protective, whereas others are not. Lastly, and most importantly (and the literature is replete with these sort of data), we know that if you inject cortisol into a fish it will suppress immune response. And, if you stress a fish you will increase levels of cortisol. Suggest to me that immune function is not all or none and that stress (which can be caused by all sorts of things) can cause immune function to break down. Ergo, disease may or may not occur since it depends on the physiological (in this case, immunological) status of the fish. Just my thoughts....

 

[leebca]

Human immunity is significantly different than fish immunity. Fish don't eat peanuts.

 

[SAT]

I'm having some difficulty with the "all or nothing" assertion also. This theory fails to explain a lot of observed phenomena. For instance, it should be impossible for fish and Ich to coexist in a tank without one or the other rapidly dying out (very rapidly for the fish or within a life cycle for the Ich), but I think we agree that can happen.

Lee, if you have some good theories about how Ich and the fishes immune system inter-relate that go beyond what the aquarium literature has published, I would really like to see them.

Likewise, if you have better data about the attenuation effect, I would love to see that as well. I was conservatively assuming a longer time period, partly due to personal observation of my own tank, which took much longer than 10 months, and partly because Burgess & Matthews reported only a very limited set of data points.

I don't suppose you have considered summarizing your work in Reefkeeping?

 

[leebca]

I'd recommend you obtain a book on immunology. One that you find you can easily read. Most of what we know about immunology of course is human based, and the second level is animal based.

Fish immunity is 'weak' by human and mammal standards.

I gave the reference for Burgess & Mathews. Beyond their work, I only have my own work. I guess it's easy to say 'There isn't enough data.' But good Lord, it's hard enough just to get any data! How many pieces of data are enough? Maybe you could write Burgess and tell him he's short X pieces of data and would he repeat his work.

The viability of a particular parasitic organism can be estimated at considerable expense. The next time you think you have Cryptocaryon irritans that refutes the above data, without the introduction of any other parasites or new MI, please have it tested by a microbiologist/ichthyologist. It would be worth a study. Until I have contra-data to review, I'll stick to the data that is available.

As I've pointed out elsewhere, first there must be positive identification. Then there must be controls. But in the case of the aquarist, identification is mostly a guess by eyesight and there is ample opportunity for the aquarist to introduce more Marine Ich during the so-called 'isolation' stage (e.g., poor control). My work was done on tanks of fish kept to grow Cryptocaryon irritans and not meant to keep fish. It's this kind of test and experimentation that yields info on the organism. That is, the culture was isolated and that became the test, not reefkeeping, Stuart. This fundamentally separates the anecdotal from the controlled experiment, even though in both my and Burgess' case, we stumbled upon the same outcome.

It should be clear why human immunity doesn't compare well with fish immunity. Humans have up to several babies in our lifetime. The fish can have many thousands. Our bodies developed a means to defend us with a strong, sophisticated immune system -- attacks from the air, soil, liquids, and exchange of bodily fluids, in an environment that has many ongoing changes in quality and stresses. Their bodies developed to reproduce in huge numbers in a relatively stable environment. Their energy/resources are spent in reproduction. Simply put, their main source of disease is by water.

For instance, it should be impossible for fish and Ich to coexist in a tank without one or the other rapidly dying out (very rapidly for the fish or within a life cycle for the Ich), but I think we agree that can happen.

Why do you assume I would agree to that 'impossible' assumption?

The parasite doesn't kill its host. If it did it would be committing suicide. This is basic biology. This refutes such the assumption you've suggested. There are ways around the situation, which Nature provides. It's imbedded in the immunology, physiology, and physical characteristics of the parasite and host relationship. In an aquarium we skew this relationship, but we don't turn it into an absolute impossibility.

Publish in Reefkeeping basic immunology? Not my game. 'My' studies (testing matrix, data, cultures, results, conclusions) are the property of those who sponsored it. That was our agreement. I cannot publish. I can only 'discuss' according to the terms of the contract. It's not my intellectual property.

Onward and upward! :rollface:

 

[Rondelet]

<a href=showthread.php?s=&postid=7118757#post7118757 target=_blank>Originally posted</a> by leebca
Human immunity is significantly different than fish immunity. Fish don't eat peanuts.

Lee,

Yes fish don't eat peanuts - but that wasn't the point. Further, while I agree that 'comparatively' piscine immunology is markedly different from mammalian immunology - there are a surprising number of similarities in form and function. Many people think the immune system in fish is primitive - but I would disagree and think that it's rather highly evolved. The problem is that we just don't understand it very well. This is due to a lack of research tools, reagents, test systems and, in particular, funding when compared to the dollars spent on understanding mammalian immune function in the pursuit of advancing human medicine.

I must say I was kind of following your logic with respect to facts and observations - until you made the claim that immunological development is linked to fecundity! I have read many books and papers on immunology (some even with big print) and have never come across this idea. Although I might not be reading the right books . Also, I wouldn't say FW environments are stable (and many SW environmentst for that matter). The main issue is not the route of transmission but rather what is being transmitted. All the usual suspects including bacteria, virus, parasites and even prions invade fish! The reason fish are not extinct is that their immunology has evolved in concert with the various pathogens and ailments that coexist with them.

At any rate, I just wanted to leave you with one more salient example (since you didn't care for the peanutsââ"šÂ¬Ã‚¦). My background in fish immunology is linked to spending many years in the development, use and evaluation of vaccines (which means I do have a better than average understanding of fish immunology). Vaccines are great research tools for understanding immunological function. If you immunise a fish and then challenge it with the pathogen you've immunised it for, it is well documented (both clinically and in the literature) that protection will vary with time depending on variety of factors. Using a very simple model, challenge the fish after a certain post vaccination interval (during which immunity develops) and you will see a certain level of protection. As time goes on, however, protection will begin to fall. To compensate, adjuvants and boosters are often used to increase immune response (to challenge). What this suggests, to me and many others I'm sure, is that the immune system is not static and can fluctuate due to variety of both internal and external influences with respect to how well it will function to protect a fish (or any other animal for that matter). So I would say that successful attack by Cryptocaryon is a matter of resistance by the host, which can be variable. I really hope you do not advocate that a stressed animal is equally susceptible to a non-stressed animal (in this case a fish). Because that is clearly not a correct concept.

Sorry to be a stickler on this point - but to not be would be tantamount to suggesting to aquarists visiting this board that it doesn't matter if you do not look after fundamental things like water quality - and other factors which may lead to stress in fish under their care.

Cheers,