Ich Immunity

[Paul B]

It has always interested me why some tanks are plagued with ich and others seem immune. Most of us know all about the Ich life cycle but I believe we are missing something. Many of us have tanks where we know ich is happily living but causing no harm while other tanks just can't seem to keep anything alive. I know when my tank was new I was one of those people who had to keep copper in there continousely. Now my fish, including so called "Ich Magnet" hippo tangs are immune. My theory is that very healthy fish in breeding condition rarely get ich although I don't know why. Ich is a paracite and not a "real" disease. It is not internal, not a bacteria or virus so our fishes immune systems should not be able to launch a defense. but somehow it does. To me it seems it would be like being immune from gun shots.
I know there are theories about an immunity or partial immunity but I really don't see how that is possable.
I know that either my tank conditions or "immunity" if you will repels ich infections but I also know that ich is alive and doing well in my tank.
I have many times introduced fish with ich into my tank and the fish will either die or get cured but never will it affect other fish. I wrote about this before and I bring it up again because last week I bought a Shark Nosed Gobi, that seemed healthy so introduced it into my tank. I do not quarantine and have not in many years (my tank is wierd so you should always quarantine)
After a few days I noticed that gobi was full of ich to the point that I knew it would be dead in the morning. I caught it and cured it with copper in another tank. None of the other fish have ich and I know from experience that they will not get it. The other six or so shark nosed gobies in the LFS from the same shipment died in the store.
Does this happen to anyone else? I personally thing it is either a tank condition or a general health factor.
Anyway it is something that I think about and it bothers me that I don't yet know the answer.
Take care.
Paul

 

[JNye]

i'm going through my second round of hypo right now. the first round I had a yellow tang and he is still in the new tank. I quarantined everything after that battle. somehow it got in my new display. I guess it was on a frag or something. I will be putting a coral quarantine in the future. But back to your point, my purple tang contracted it first and i tried fighting it for weeks with garlic, heavy feeding and see if he could fight it off. this went on for 2 months, at least 2 life cycles prolly a few more. they got just too bad and started showing on my goldstripe clown so i decided it was time to treat everyone. through all this time my yellow tang never showed a sign of ick, as he has already had it bad and was cured of it...still haven't seen any sign of it to date(on the yellow). I just got my SG to 1.009 tonite so 30 days to go!
so i agree with the immunity but don't understand it totally. viruses are parasites too in a way,(internally) and you can develop immunities to them, so it isn't that hard to believe.

 

[lecher]

I've never understood how a fish can develop immunity to ich parasites. To me it would be like saying a dog can develop immunity to fleas or people can become immune to mosquitoes. It is weird how some tanks don't seem to develop outbreaks even though the parasite is present. Perhaps tank parameters somehow play a role in disrupting the life cycle in certain tanks or maybe there are some fish immunological factors involved. Interesting food for thought.

 

[coralnut99]

My experience is very similar. I have 3 different displays, and a 3 tank prop system. My last encounter with ich was about 2 years ago when a purple tang got it after I introduced a trio of tri-color anthias. The outbreak went away by itself in less than a week. The only fatalities I seem to incur are those where a dominant fish in the tank refuses to let new ones out of the rocks, and the new fish will slowly succumb to wounds and secondary infections. So I would say my experience is very similar with regard to ich, and my conclusion is just a very simple reasoning that healthy, stress-free fish just don't contract ich.

 

[Paul B]

Perhaps tank parameters somehow play a role in disrupting the life cycle in certain tanks or maybe there are some fish immunological factors involved. Interesting food for thought.

Lecher, that is the reason I started this thread. Most of us know the life cycle of ich but there is more we don't know. It is not the same in all tanks and I do know that a stressed fish, even if he is in my tank will exhibit ich. If I keep them healthy in other ways, ich is never a problem. If a fish is spawning that is a good indication that the fish is about as healthy as it is going to get. If your fish are not spawning or at least exhibiting spawning behavior like clearing a nesting area or chasing males, they may not be as healthy as you believe. This does not apply to all species of fish. You may not see tangs or other egg scatterers doing this.
Paul

 

[lecher]

Yeah, I've always heard that healthy fish usually don't develop clinical ich infections. It just never made sense to me how it could be. I wonder if anyone has done studies to try to isolate ich antibodies in fish. Perhaps the blood of a healthy/ stress free fish has something in it, possibly a hormone, that the parasite does not like. I have no idea, just taking stabs in the dark. Wish I had the time and resources to conduct research. It would be very interesting.

 

[Untamed12]

My (seemingly quite healthy) Achillies Tang develops minor ich each time a new fish is introduced. I suspect this is more to do with the stress created by the new fish, than any specific introduction of "new ich".

This continues for about 2 weeks, when the Achillies will return to ich free and remain that way until the next fish introduction.

To my knowledge, ich has not killed any fish in my care even though I live with it constantly...do not quarantine...and do not attempt to medicate or treat an affected fish. (maybe 15 years that I've been doing this) It seems to me that lack of stress and general health seem to make a fish resilient to ich. Like you, I cannot understand why that would be.

 

[liveforphysics]

I am thankful for my system's Ich immunity. It helps me get lots of "rescue fish" that way. They always ask if I have some special QT tank method to save the Ich covered fish. I tell them, Yup! It's my display tank.

I have 6 species of tang, a pair of asfur angels and lemon peel angels, 20+ anthias and other ich prone species. I will throw an ich covered fish into the tank anytime somebody gives me one to save. On occasion, a few of the other fish, often the tangs, will have a few little spots appear on them here and there for a few days, then everything just starts to vanish like a magic trick. Often inside of a week no fish will have signs of Ich.

I think super low stress enviroments and fish with thick natural slime coats are helpful, but I'm not convinced that is the entire reason.

Perhaps we can find trends in common with tanks that have Ich resistance/immunity.

It's a 310gal sps/mixed reef with a pair of 60gal refugiums on staged lighting.

No skimming, No waterchanges. Chaeto growth is the only nutrient export. Calcium reactor and 3-part dosing maintains ballance in the big 3 ions.

Feeding includes a huge variety of foods. I often catch a net teaming with natural pods and shrimp scooped up from the Tacoma waterfront. I also spend a few minutes scraping big chunks of puget sound sponge off the docks when I happen to be driving by at a very low tide time. The fish will gobble the sponge over any other item I feed, includeing newlife spectrum, which is the core of the diet. All fish gobble the sponge, even gobys and anthias and fish you wouldn't expect to want sponge. When I dump a net full of live tiny shrimp and pods of a variety of species into the tank, it's a water frothing feeding frenzy. They manage to gobble a few thousand little zooplankton animals in about a minute or two. Then they spend lots of time hunting them in the cracks of the rocks and things. It looks very natural to see them hunting live foods rather than sitting waiting for pellets. I also feed the fish bananas and pears and let them pick clean apple cores that I hold for them.

The fuges are both thick with zooplankton. You can actaully watch by the suction lines to the return pump to see unlucky zooplankton be sucked in. The return pump is a dart, and I and confirm that very often the zooplankton is not killed by the pump.

I also drop in capsules of ammino acids made for humans to swallow, and sometimes squeeze a lemon or orange into the tank. I sometimes dump a scoop of creatine powder into the tank as well.

Flow is very extreme and simulates wave pulses. Lighting does a 7 stage intensity transition, and is correctly synched with natural sunrise/sunset. The lunar period is also linked, but it's kinda half-assed becuase intensity is constant, only period changes. I'm going to correct that when I get time.


Hopefully we will find some trends common in tanks that have Ich resistance/immunity. That could greatly help the reefkeeping comunity and save many fish lives.

 

[greenbean36191]

Developing an immunity to ich is nothing at all like developing immunity to gunshots or mosquitoes. Ich is a disease caused by protozoan parasite, just like malaria. All it takes to develop an immunity is to prevent the parasite from completing the stages of its lifecycle within the host. In FW which is nearly identical, the immune system produces specific antibodies that immobilize the parasite and break the lifecycle. The antigens from the parasite have been used to create experimental, but effective vaccines for the disease. There's clearly an immune response to SW ich, though it's not known if it works the same way as with FW ich. We do know though that fish subjected to higher initial infections of the parasite are more likely to develop resistance and harbor fewer parasites on subsequent infections. Stress suppresses the immune system, so it's not surprising that stressed fish often show visible infections when previously they may have only been carriers.

 

[MYDRAAL]

GB, will a fish that has won the battle with ich completely end its life cycle or will it always be a carrier?

 

[Paul B]

Feeding includes a huge variety of foods. I often catch a net teaming with natural pods and shrimp scooped up from the Tacoma waterfront. I also spend a few minutes scraping big chunks of puget sound sponge off the docks when I happen to be driving by at a very low tide time.

Liveforphysics, we have that in common. I have been doing that sinse the seventees. Only I take a net into the Long Island Sound to collect plankton, amphipods, copepods, seaweed etc. I also scrape sponge off the docks.
I doubt this would have anything to do with it unless we can find other people who do this. I just know it is very healthy for the tank, not only because of the food but because of the varieties of bacteria we are adding. I have always believed that captive reef tanks are much too sterile. If all of your animals and rock comes from a store then you only have the few types of bacteria in your tank that they have in the store which may not be the most beneficial types.

Greenbean I think ich may be different from Malaria in that malaria is an internal paracite that is circulated around with the blood. There are antibodies in the blood that can attack the malaria paracite. Unfortunately in humans, our antibodies do not recognize malaria paracites and medication is necessary.
In Viet Nam I, and everyone else had to take two anti malaria pills every day and continue taking them for six weeks after returning home. I would like to find out what it was and experiment with it.
I am glad you brought up Malaria though because to cure ich I use copper plus a malaria medication called Quinicrine Hydrocloride. This combination will clear a fish of ich in a day. Of course it needs to remain in the treatment for ten days just like copper alone.
The quinicrine is not too toxic to inverts like crustaceans but it will kill corals and it is not as effective without the copper.
Paul

 

[EnderG60]

my experiances have been similar. Ive never lost a fish to ich. Only times I ever see it are when a fish is stressed, usually the blue tang, and it never lasts more then a week.

Hell I just swapped some tangs out in my tank(they got big and I got smaller ones) and what do ya know the blue got stressed and started doing up downs in the corner and ich. Two days later not a sign of it, and he was back to his usual self.

When I see extreme cases, I usually tell people to just up the temp and feed the hell out of them(with garlic just for good measure) In just about every case where the fish wasnt getting its butt kicked, they would recover in a week or two.

I truely believe, there is no ich immunity, every tank has it, and the ich is a symptom of stress and not a reason for it or death.

 

[Whalehead9]

Friend of mine has a powder brown tang that always has it. It can be covered one day and down to completely clean, only to go back through the whole process. No other fish have it. None have ever gotten it, and the whole tank has been treated more than a few time, and the infected fish pulled and treated also. In the end it is simply the fish that will always have ich.

There has to be a stressor of some sort, but he has not been able to figure out what it is? It eats like a pig no matter how many parasites are on the body.

I think that some species of fish are more prone to this kind of infestation than others, and any kind of stress can bring out the white spots in mass.

 

[Paul B]

Stress will let you see the paracites because they will be visable as they go through their life cycle. Ich IMO is always in most but not all tanks. You can keep it out by quarantining everything which is the way many tanks are maintained. Unfortunately, if you do introduce ich you need to make sure your fish are healthy enough to fend it off. There is some thought that ich imparts some sort of temporary immunity in the fish slime but I am not quite convinced yet.
Paul

 

[greenbean36191]

GB, will a fish that has won the battle with ich completely end its life cycle or will it always be a carrier?

There are probably cases where they completely get rid of the parasite, but IIRC in the study that looked at immunity, the fish all still harbored a small number of parasites.

Greenbean I think ich may be different from Malaria in that malaria is an internal paracite that is circulated around with the blood. There are antibodies in the blood that can attack the malaria paracite. Unfortunately in humans, our antibodies do not recognize malaria paracites and medication is necessary.

The immune system will attack anything it recognizes as foreign in any tissue, not just the blood. Whether or not the parasite has tricks to beat the immune response (like malaria) is a separate question. The ich parasite is completely embedded within the outer tissue layer of the skin or gills and can easily be attacked by the immune system.

In FW ich the infection mechanism and lifecycle is nearly identical, so it's highly likely the immune response is similar. The body recognizes proteins on the surface of the parasite and creates antibodies against them. They attach to the parasite, immobilize it, and eventually it dies without completing the lifecycle. You can inject the fish with the surface proteins and induce the production of antibodies against the parasite, so if it encounters it in the future the antibodies are there waiting to kill the parasite. It doesn't prevent the parasite from entering the fish's body, just from being able to complete its lifecycle and produce more generations to infect in the future.

 

[liveforphysics]

Great info Greenbean! I had not realized how it functioned that the immune system is able to stop ich on it's own, I only knew that they get well on there own in a good enviroment.

This leaves me with a question. When I get a rescue fish covered in ich from someone, I toss it into freshwater+copper bath for a few minutes, then a freshwater rinse and then into my display. They always still have the ich spots on them. Each day they have less and less spots until they eventually don't show any. Does this mean that the fish gains immunity this fast? Does the mob of cleaner shrimp and cleaner wrase always cleaning the fish with Ich play a big roll in this? I've heard they have no effect at all, but from watching they seem to definately be removing things from the fish, which seems like it would at least relieve stress for the fish.


Thanks for your input!
-Luke

 

[greenbean36191]

Without looking at what's going on with the ich histologically there's really no way to really say what's going on. Like I mentioned earlier, the immune response to SW ich is poorly studied. We know it happens and the presumption is that the mechanism is similar to FW ich, but no one really knows. I suspect what you're seeing is due to a combination to the immunity and some of the parasites just completing the lifecycle and dropping off the fish, but that's just an educated guess. In the study that looked at this, even the fish with the strongest resistance to the parasite never gained full immunity, so clearly some of the parasites were still able to complete their lifecycle.

There's really no evidence the cleaners help anything and in fact, when you remove them from the reef parasite loads don't change. The popular thinking is that in captivity where the parasites that they are known to eat aren't a problem they're just removing damaged skin, which is actually what the white spots that we see are.

 

[Paul B]

To update, that shark nose gobi I bought that was loaded with ich was cured in copper for a few days and has been in my reef for a week. All signs of ich are gone as are the scars.
The fish is voracially eating new born brine shrimp and I know from experience that he will no longer be affected by the disease.
As I said, all of the rest of them in the store died from ich.
Paul

 

[Philwd]

My experience is stress will indeed cause deadly outbreaks. Recently I added a rhomboid pair to my tank. To ease introduction I put them in a small acrylic chamber to let the other wrasses get used to them. Release after a couple days. Has worked well with other fish and never triggered an outbreak. (Just a bit of background. The rhomboids came from a local LFS that QTs every fish in a separate individual system for 2 weeks with a variety of meds. These fish were clean when I brought them home.)

Did the same thing with this new pair. However this time a condei wrasse decided he would not chase but hunt the new male. This went on for 2 days. Stressed out every fish in the tank. Third day I caught the condei and put him the acrylic holding chamber till I got the QT running. By third day EVERY fish was covered in 20-30 spots. Not just the new introduction. I lost 4 fish to that outbreak. First 2 fish I lost were long established. The rhomboid went third. Seemed my biggest fish were the ones that succumbed.

Only fish that didn't get a spot. The aggressor condei.

 

[sunfish11]

I have also never lost a fish to ich although I have added fish with ich to my display. They cleared up on their own. My achilles tang (added Dec 6, 2007) developed a bad case 4 days after he was introduced to my tank. None of the other fish had spots. The tang cleared up on his own in a couple of weeks and is fine now. I also feed a varied diet and fairly heavily. I treat ich by feeding the heck out of the fish that has it. When I get a new fish I break up feeding 4 X5 times per day. Once they get comfortable in thier new environment and are eating well it clears up. Ich is definitely stress related IME. It also stands to reason that nutrition plays a vital role in fending off Ich.

Lisa