Protective immunity against Cryptocaryon irritans

[Humblefish]

This entire article was written by ThRoewer and is being republished with his permission:

This seems to be the standard reply around here:

A small number of fish develop temporary immunity to the strain of cryptocaryon irritans they encounter. However, they are carriers of that strain and can infect other newly introduced fish.

But if you read the actual works on this and not just the overly simplified and rather careful worded abstracts, the picture is quite a bit different:

Most (if not all) otherwise healthy and fit fish will develop immunity to Cryptocaryon irritans after surviving a non lethal infection and then enough rest to recover.
They will maintain this immunity as long as Cryptocaryon is present and their immune system is not compromised through stress or other external factors.

The level of immunity seems to relate to the level of the immunizing infection. While not being tested in those studies I assume the level of immunity may also increase with duration of exposure, at least that is what my personal observations indicate.

Not fully immune fish may of course be carriers of the infection.

Burgees' tests (1992 Dissertation) showed that all exposed fish acquired immunity and that this immunity will last at least 6 months without the presence of Cryptocaryon.
Fish challenged wit a lethal dose after 3 months were 100% immune (no infection could be found).
After 6 months 2 previously unchallenged fish were challenged with a lethal dose of Cryptocaryon but only contracted a minor infection.
None of the immunized fish died due to challenge with a lethal dose in any of the studies.

Other studies had different timelines but otherwise corresponding findings.

There have been plenty of tests on this under laboratory settings but they usually only had a single non lethal immunization exposure and a single challenge.
I have not yet found any repots on long term exposure studies. Though my own observations and those of others here indicate that most fish may actually gain full immunity in the prolonged present of Cryptocaryon and that the parasite eventually will die out due to lack of suitable hosts in the system unless reintroduced with new acquisitions.
From my observations I would also assume that this immunity is not strain specific.

Fish that are under constant stress may only gain partial or no immunity. This includes being constantly sick with Cryptocaryonosis.


Here are some more recent works on this I could find in full text versions:

Protective immunity in grouper (Epinephelus coioides) following exposure to or injection with Cryptocaryon irritans
X.-C. Luo et al. / Fish & Shellfish Immunology 22 (2007) 427e432
http://scsagr.scsfri.ac.cn/upimg/200853010029.pdf

Misumi, I. 2009
THE CILIATED PROTOZOAN PARASITE, Cryptocaryon irritans, AND PROTECTIVE IMMUNITY IN MARINE FISH
http://nsgl.gso.uri.edu/hawau/hawauy09002.pdf


Now, that nobody get's me wrong: this is not a call to skip QT or not do TTM or other preventive measures.
Even if Cryptocaryon is not of concern there are plenty of other diseases that can kill your fish.
Also, most do not keep their fish in a stress free environment. For example any tang in a too small tank will be too stressed out to ever gain full immunity, and most tanks are way too small for the tangs kept in them.

 

[Humblefish]

It seems the same immunity responses exist for Amyloodinium and likely all other protozoan parasites.

Acquired immunity to amyloodiniosis is associated with an antibody response.

Abstract

The dinoflagellate Amyloodinium ocellatum, which causes amyloodiniosis or 'marine velvet disease', is one of the most serious ectoparasitic diseases plaguing warmwater marine fish culture worldwide. We report that tomato clownfish Amphiprion frenatus develop strong immunity to Amyloodinium ocellatum infection following repeated nonlethal challenges and that specific antibodies are associated with this response. Reaction of immune fish antisera against dinospore and trophont-derived antigens in Western blots indicated both shared and stage-specific antibody-antigen reactions. A mannan-binding-protein affinity column was used to isolate IgM-like antibody from A. frenatus serum. The reduced Ig consisted of one 70 kD heavy chain and one 32 kD light chain with an estimated molecular weight of 816 kD for the native molecule. Immunoglobulin (Ig) isolated from immune but not non-immune fish serum significantly inhibited parasite infectivity in vitro. An enzyme-linked immunosorbent assay (ELISA) was developed using polyclonal rabbit antibody produced against affinity-purified A. frenatus Ig. Anti-Amyloodinium serum antibody was not always detectable in immune fish, although serum antibody titers in immune fish increased after repeated exposure to the parasite. These results suggest that there may be a localized antibody response in skin/gill epithelial tissue, although antibody was rarely detected in skin mucus.

It seems also that acquired immunity may in some cases even be transferred to naïve fish in the same system or passed on to offspring:

Immunization against parasitic diseases of fish.

Abstract

Parasitologists have not, in the past, exploited the immune system to protect fish against parasitic diseases. In the past few years, however, there has been an increased interest in adopting this strategy, and we have made steady and promising progress against a few parasites which are of economic importance. Amyloodinium ocellatum is an ectoparasitic dinoflagellate on brackish and marine fishes, which may also cause problems to aquarium fishes. Antiserum from fish inoculated intraperitoneally (i.p.) with living dinospores of the parasite immobilizes and agglutinates living dinospores; it also reduces parasite infectivity in cell culture. Cryptobia salmositica is a pathogenic haemoflagellate of salmonids on the Pacific coast of North America, causing mortality in semi-natural and intensive salmon culture facilities. A live attenuated vaccine inoculated i.p. protects susceptible juvenile and adult fish for at least 24 months. The protection involves production of complement fixing antibodies, phagocytosis, and antibody-dependent and antibody-independent T-cell cytotoxicity. A monoclonal antibody against a surface membrane glycoprotein (199-200 kDa is therapeutic in that it significantly reduces parasitaemias when inoculated into fish with acute disease. Ichthyophthirius multifiliis is an ectoparasitic ciliate of freshwater fishes with world wide distribution, usually causing disease when fish are stressed and/or when environmental conditions are favourable for parasite multiplication. Live theronts injected into the body cavity protect fish, and monoclonal antibodies with immobilizing activity upon parasites have been developed. There is some evidence of passive transfer of protective immunity from immune to naive fish, and to eggs. Diplostomum spathaceum is an intestinal parasite of gulls; the metacercaria stage of the parasite encyst and causes disease and mortality in numerous species of freshwater fish in Europe and in North America. Fish injected i.p. with sonicated/killed cercariae or metacercariae have fewer metacercariae in the eyes and survives longer. Lepeophtheirus salmonis and Caligus elongatus are parasitic copepods (sea lice), and they are important parasites of Atlantic salmon in cage cultures. A vaccine against fish lice is plausible, and the efficacy of about 20 candidate antigens in protecting fish is being tested.

Protective immunity in fish against protozoan diseases.

Abstract

The demand for and costs of producing land-based animal protein continues to escalate as the world population increases. Fish is an excellent protein, but the catch-fishery is stagnant or in decline. Intensive cage culture of fish is a viable option especially in countries with lakes/rivers and/or a long coastline; however, disease outbreaks will likely occur more frequently with cage culture. Hence protective strategies are needed, and one approach is to exploit the piscine immune system. This discussion highlights immunity (innate/natural and adaptive/acquired) in fish against three pathogenic protozoa (Amyloodinium ocellatum, Ichthyophthirius multifiliis and Cryptobia salmositica). Histone-like proteins in the mucus and skin of naturally resistant fish kill trophonts of A. ocellatum, and also may cause abnormal development of tomonts. Breeding of Cryptobia-resistant brook charrs is possible as resistance is controlled by a dominant Mendelian locus, and the parasite is lysed via the Alternative Pathway of Complement Activation. Production of transgenic Cryptobia-tolerant salmon is an option. Recovered fish are protected from the three diseases (acquired immunity). Live I. multifiliis theronts injected intraperitoneally into fish elicit protection. Also, a recombinant immoblizing-antigen vaccine against ichthyophthirosis has been developed but further evaluations are necessary. The live Cryptobia vaccine protects salmonids from infections while the DNA-vaccine stimulates production of antibodies to neutralize the disease causing factor (metalloprotease) in cryptobiosis; hence infected fish recover more rapidly.

 

[Humblefish]

This might also be of interest:

Studies on Amyloodinium ocellatum (Dinoflagellata) in Mississippi Sound: natural and experimental hosts (Full PDF here)

Abstract

Four species of parasitic dinoflagellates have been found to occur naturally on the gills and fins of Mississippi Sound fishes: Amyloodinium ocellatum (Brown 1931) Brown and Hovasse 1946, Oodinium cyprinodontum Lawler 1967, and two undescribed species. Sixteen of 43 species of fishes examined had natural gill infections of A. ocellatum. Seventy-one of 79 species of fishes exposed to A. ocellatum dinospores were susceptible, and succumbed, to the dinoflagellate. Eight did not die even though exposed to numerous dinospores. The most common signs in an infested fish were spasmodic gasping and uncoordinated movements. Trophonts of A. ocellatum were found on the gills, skin, fins, eyes, pseudobranchs, membranes of the branchial cavity and around the teeth; and in the lateral line pits, nasal passages, esophagus, and intestine of experimentally infected fishes. The dinoflagellate causes extensive mortalities of fishes held under closed-system mariculture conditions

 

[Humblefish]

All of the above was provided by the ThRoewer. Below is a comment that was made by another poster that I found interesting:

Fish that are newly acquired are not often healthy and fit. Furthermore, many are placed in environments that are stressful (aggressive neighbors, over crowding, insufficient feeding, etc). Depending on immunity, IMO, will result in some unhappy aquarists. Studies rarely provide all variables and often do not match aquarist environments. A great intellectual treatise . . .

 

[Paul B]

I have been saying this for years but most people don't seem to believe it which is the reason for all the disease threads. My own tank seems to be immune from everything from what I can tell. I remember Burgess studies but that was in the early 90s. The problem with scientific studies is that they only last a few months or until the funding runs out. I have been studying this for 40 years and unlike virtually everyone, I like parasites because first of all they are natural and evolved right alongside our fish, but they are part of what the fish are. The fishes immune system is very capable of negating the effects of parasites because they are constantly bombarded with them in the sea. More so in an aquarium because the ratio of parasites to water is much more in a tank. But in the fishes defense, there will be fewer "types" of parasites present in a tank even though there may be more numbers of that particular parasite. After the parasite tries to get through the fishes defenses and the fish builds up an immunity, the offspring of that parasite will have a much harder time of infecting the fish because of it's immunity.
I feel we strive to much on keeping diseases away from our fish which is totally un natural, then we try to cure them when they get sick because fish that are kept away from pathogens will in time, have no functioning immune system. The immune system in fish (and us) constantly depends on meeting disease organisms. The immune system in fish requires an enormous amount of energy to function. The slime fish exude constantly is a large part of it''s immune system and if no disease organisms are ever present the fish will lose the ability to make antibodies in it's slime just like cave fish, over time lost their ability to have eyes as eyes take up a lot of energy to make and function. Doctors today are severely limiting their use of antibiotics they give us because they have learned that it is better to allow our immune system to cure us which is how we are made other wise,antibiotics will have to be used whenever we are exposed to a pathogen. Our immune system and a fishes immune system requires pathogens to remain healthy. Only the proper food along with a few other things will accomplish this. I didn't make this up, besides my own experience I have read all those studies you linked and many more.
We already had a long thread on this that I started a while ago.
https://www.reef2reef.com/threads/a-discussion-on-immunity.209701/

 

[Humblefish]

@Paul B I think the quagmire is most fish arrive to us in such bad shape that they never get the chance to acquire protective immunity. Which is why you must still QT to at least condition your fish, even if the end result is putting him in a DT where ich is known to be present. :eek:

 

[Paul B]

Fish certainly do come in bad condition we will all agree on that. We need to get the correct food into those fish as soon as possible to hopefully protect any immunity the fish still has. It is true that some fish should not be put into a mixed reef until we fatten them up a bit but I personally would not quarantine them for a long period. That is just me and I realize I am in the vast minority. I very rarely lost a fish after putting it in my tank unless I purposely bought it knowing it was very sick and I got it for practically nothing because the dealer figured it would have a better chance in my tank than his. But my tank is very natural and close to the sea because I dump stuff from the sea into my tank all summer. There is always something to eat in my tank as the amphipods multiply all year and are under all the rocks just as they are in the sea. I get a lot of flack for my theories and can't even mention immunity on some, well one forum. I always say, I am not the God of fish so make up your own mind on how you want to care for your fish. There are many ways to come to the same end result. :D

 

[Humblefish]

This is going to be purely anecdotal but here goes ;):

I have been watching this one Kole Tang over at my local Petco for weeks now. He looks flawless, has a very good appetite, swims normally, doesn't rub on rocks, etc. What makes this unusual is all his (fish) tankmates keep dying left & right. No physical evidence of velvet, but most of the dying fish have all the telltale behavioral symptoms: labored breathing, scratching/flashing, swimming into the flow of a powerhead, etc. What makes this a little tricky is I have gotten fish from this Petco with both velvet & brook, so without visible physical symptoms to go on its impossible to say which disease is in this tank. But I believe velvet because it's taking down even parasite resistant & hardy species such as wrasses, gobies... even all the damsels are dying. :eek:

Just wanted to share an interesting observation. :)

 

[Paul B]

Of course there are parasites in that tank, but (as I have been saying for years) that tang is immune and if he keeps getting the proper food, he will stay immune like all our fish are supposed to do.

 

[sundog101]

These studies are really interesting. What they need to do is take some ich/velvet and zap it with a uv sterilizer to keep it from reproducing and then dose it to a tank. But it seems like there are other factors affecting immunity and not everyone keeps their fish in a stress free environment.

 

[Paul B]

True, but they should. :)

 

[Humblefish]

Of course there are parasites in that tank, but (as I have been saying for years) that tang is immune and if he keeps getting the proper food, he will stay immune like all our fish are supposed to do.

Question is how did this fish build up immunity, when none of the others did. They all came from the same wholesaler and receive the same care/nutrition from Petco after that. I wonder if the Kole Tang was exposed to a small concentration of velvet dinospores in the wild, so now his immune system is able to recognize it & fight velvet off more adeptly.

 

[BoneXriffic]

I may be experiencing this, my tank was taken by what seems to be velvet. 3 fish died, in a quick fashion. A sailfin tang, the carrier. A bicolor blenny. And the last to die my occelaris. The clown was not hosting. The remaining 2 fish, a blue damsel (named terminator because death seems to fear this fish) and a hosting snowy onyx clown. Both have receding white spots and have been covered with what appears to be velvet for 3 weeks now.

As humble knows. What are the thoughts on these two becoming immune?

The remaining clown that hosts, i thought the nem maybe helped. But more reading the consensus seems that nems reduce the slime coat on a clown making them more susceptible to death...

I an to read through these articles, thanks guys for the good info

 

[Humblefish]

What are the thoughts on these two becoming immune?

The problem with immune fish is they are still likely carriers, capable of infecting non-immune fish. So, all your fish would have to develop immunity to "live with the problem" in your tank. Paul's fish likely have natural immunity because they are so old. But most new fish arrive to us in bad shape, and getting a fish into "breeding condition" (as Paul likes to call it) doesn't happen overnight. So, you would still need to QT all new fish to condition them to go into a known diseased environment. And hope the fish's immune system can handle whatever nasties are lurking there. That's too much unpredictability for my liking.

 

[BoneXriffic]

The problem with immune fish is they are still likely carriers, capable of infecting non-immune fish. So, all your fish would have to develop immunity to "live with the problem" in your tank. Paul's fish likely have natural immunity because they are so old. But most new fish arrive to us in bad shape, and getting a fish into "breeding condition" (as Paul likes to call it) doesn't happen overnight. So, you would still need to QT all new fish to condition them to go into a known diseased environment. And hope the fish's immune system can handle whatever nasties are lurking there. That's too much unpredictability for my liking.

I want this disease gone. But that said, would qting these immune fish shed the dosease or are they forever carriers?

 

[Cabinetman]

I

I have been saying this for years but most people don't seem to believe it which is the reason for all the disease threads. My own tank seems to be immune from everything from what I can tell. I remember Burgess studies but that was in the early 90s. The problem with scientific studies is that they only last a few months or until the funding runs out. I have been studying this for 40 years and unlike virtually everyone, I like parasites because first of all they are natural and evolved right alongside our fish, but they are part of what the fish are. The fishes immune system is very capable of negating the effects of parasites because they are constantly bombarded with them in the sea. More so in an aquarium because the ratio of parasites to water is much more in a tank. But in the fishes defense, there will be fewer "types" of parasites present in a tank even though there may be more numbers of that particular parasite. After the parasite tries to get through the fishes defenses and the fish builds up an immunity, the offspring of that parasite will have a much harder time of infecting the fish because of it's immunity.
I feel we strive to much on keeping diseases away from our fish which is totally un natural, then we try to cure them when they get sick because fish that are kept away from pathogens will in time, have no functioning immune system. The immune system in fish (and us) constantly depends on meeting disease organisms. The immune system in fish requires an enormous amount of energy to function. The slime fish exude constantly is a large part of it''s immune system and if no disease organisms are ever present the fish will lose the ability to make antibodies in it's slime just like cave fish, over time lost their ability to have eyes as eyes take up a lot of energy to make and function. Doctors today are severely limiting their use of antibiotics they give us because they have learned that it is better to allow our immune system to cure us which is how we are made other wise,antibiotics will have to be used whenever we are exposed to a pathogen. Our immune system and a fishes immune system requires pathogens to remain healthy. Only the proper food along with a few other things will accomplish this. I didn't make this up, besides my own experience I have read all those studies you linked and many more.
We already had a long thread on this that I started a while ago.
https://www.reef2reef.com/threads/a-discussion-on-immunity.209701/

m with you Paul. I've got a tank full of tangs and I know they are immune to ich. One parasite I think gets misdiagnosed and is harder on fish is flukes. I had what I thought was a bad outbreak a few months back which threw me because my fish never get sick. Turns out it was flukes. Nice thing about flukes is prazi pro is reef safe

 

[Paul B]

I really don't like these disease threads because I feel it should not be an issue. Humble knows that I think fish should "never" get sick. If they "never" get sick in my tank, they should never get sick in anyone's tank. Of course we need to keep fish in breeding condition but that is easy. If we don't want to, or for some reason, can't keep fish in breeding condition we need to quarantine everything, all the time because the fish "will" get sick and they will get sick from "everything". It is simple. My fish are not all old. I have a couple that are only a few months old and they also came from stores with a lot of sick fish. I am not actually sure why for some reason they don't get sick but the only thing I can think of with new fish is that every meal they get in my tank is composed of food that have live bacteria in them. My foods, for the most part all contain only one ingredient such as worms, clams, Mysis, baby brine shrimp etc. I never feed dry because I feel it doesn't have any live bacteria, doesn't have any oils and has preservatives. I may occasionally put some pellets in for something hiding in a cave only because I want to soak those pellets in fish oil, but I usually don't have to do that and the only things I feed that to now is the pistol shrimp hiding in a cave. I shoot it in there, but nothing else gets dry foods. I believe fish need live bacteria "every" meal to keep up their immune system. Most processed foods do not have live bacteria. LRS foods do and they also have pro biotics so they would also be good. But whatever we do, fish need live bacteria to maintain their immunity. If your fish don't get live bacteria, you will always be posting on a disease forum. There is no way around it. Fish in the sea have been living with parasites since way before Betty White was born. Actually parasites evolved first. Parasites live off our fish but they don't really "want" to kill our fish. Would you kill your Pizza delivery man? If your fish are immune (like they should be) and there are parasites in your tank, like all natural bodies of water) the parasites will suck up a little fish slime occasionally but the fish slime contains immunologic substances that tell the parasites, "Hey little guy, get off of me or you will croak".
This slime (especially the slime that can talk) is a huge burden on the fish to manufacture. Remember it is water soluble so it constantly washes off forcing the fish to make more. Only very healthy fish can produce slime with antibodies in it. Fish in marginal condition can make some slime, but it will not have antibodies in it, if it did, we would not have a reason to have disease threads. Fish also need to meet some parasites to know what type of antibodies to make. Just like we get inoculated for measles, polio, typhoid, flu etc. Those shots may not give us 100% protection from those diseases, but if we only ate oatmeal or some other dry food every day, we would have much less chance to stay healthy. We are not fish and we don't have to make slime. Most of us also don't live in water so we have far less parasites to fear. Fish and parasites go together like Supermodels and high heels. They naturally belong together and both the Supermodels and fish "benefit" from parasites (and high heels) Yes, I did say that, parasites benefit fish just as bacteria, and parasites benefit us. They do that by maintaining our immune system and digesting our food. Without bacteria we would be gelitanacious blobs of crypto matter sort of like jellyfish. Oh, wait! Even Jellyfish can't live without bacteria.
So if you want healthy fish, feed them correctly. If you are content quarantining for 72 days and posting on disease forums, do something else. Either way, have a great day and good luck no matter what you do. :D

http://www.saltwatersmarts.com/want-healthy-spawning-fish-feed-them-properly-5010/

http://www.saltwatersmarts.com/some-subtle-signs-fish-is-sick-5964/

http://www.saltwatersmarts.com/marine-fish-heal-through-slime-3962/

 

[Cabinetman]

Paul do you run a skimmer?

 

[Paul B]

Yes this DIY job.



And an algae scrubber. Here it is clean.



And running with algae on it.

 

[Cabinetman]

Paul in my experience my fish actually do better when I'm skimmerless and use algae as my filtration. I've always said skimmers remove something from the water that screws with the fishes slime coat. A while back when I first got started I had a huge reef lo skimmer and my fish always had ick. About a week after taking it offline my tangs all cleared up and I've never looked back. Now I'm like you, I can drop the most diseased looking fish into my display and it doesn't affect anything. And here's the kicker, I only feed nls pellets 90% of the time. About once every few weeks I feed frozen. I'm a firm believer in natural filtration and none of this hi tech stuff. Use enough algae and you'll have a bullet proof setup. Btw. I add stuff to my tank all the time too. The only thing I've ever encountered that my fish needed help was flukes. Those suckers are masty