A discussion on immunity

[mcarroll]

Well said! :)

Curious about yours and anyone else's further thoughts on this.

Fish that become ich infected are likely saved in the wild by their immune response. Even if they get infected, the first round of parasites cannot re-infect them, simply because the fish isn't contained to a small area that gives favor to the parasite. In the aquarium, it's ich's life cycle (and the life cycle of most marine parasites) that make it so deadly. They are in a closed area that is highly stocked so the opportunity for re-infection is high.

I think there's truth in that, but there's something about the immune response that tells me that the fish are supposed to get used to living with them.

That seems to be part of the idea, or after how many hundreds of millions of years the immune response would be an eradication response. But it's not.

Dilution to the sea certainly would be a factor, but most fish are social and would probably be able to maintain a community infection - particularly reef fish that may return to and share sleeping quarters.

This maintained community infection would have the effect of helping the group to exclude competition from "rival groups" that may be adapted to a different strains.

It's a thought.

 

[jeremy.gosnell]

It would be worthwhile, involving the prospect of wild community infection, to look at a species by species breakdown. Many people think that tangs are schooling fish in the wild. Some are, but many are solitary feeders that only school as a defensive mechanism to overwhelm damselfish which protect algae patches with their lives (damselfish use algae patches to construct their nests). Some species do school in a community, but often these species are open ocean travelers and the opportunity for re-infection, even in the group is low given oceanic environmental conditions. It's important to remember that ich encysts on a fish, feeds and then the cyst falls off in-tact. In the ocean, that cyst is likely carried on currents for an extended period of time, before settling. After settling, the parasite makes numerous copies of itself, breaks out from the cyst and thousands of free-swimming parasites go free. Chances are, the original parasitic carrier is long gone by then - even if they belong to a large school of fish. Reef fish behave like people on a busy city street. They show up, eat and hang out, then are off to another destination. They might do so in a group, but they aren't spending excessive amounts of time in the same general area for long - so the parasites timing would have to be perfect and not subject to coincidence.

I think on the wild reef, fishes' current immunity is enough to spare their life in most (if not all) cases of marine ich infection. Ich behaves on wild fish much like ticks or fleas do on wild forest animals. It's very rare (if ever) that we hear of forest animals dying due to a tick or flea infection. There has been enough infection and immunity to save fish over the millennia, but still keep ich around as a successful parasite. Again, even though they don't kill, fleas and ticks still exist.

It's the captive environment that poses a challenge as it favors the parasites life cycle and gives them an edge because fish cannot escape a confined area. When I worked at public aquaria we often didn't get overly concerned about ich infection in tanks that were 100,000 gallons or so, because often the parasite would just work its way out of the system without any fatalities. I do think down the road as captive breeding expands, scientists may be able to find a way to manipulate piscine parasites (like they manipulate human and animal diseases) to formulate vaccines that cover a gamut of marine parasites and are easy to administer. For now that's the reef keeping realm of science fiction, but I think easily within our lifetimes it may be science fact, especially as the hobby continues to grow.

 

[Paul B]

What they agree on is that every fish has an immune response to the external parasite, and that immune response involves increased slime coat. After around 6 months, it seems the surviving infected fish lose their immunity, much like people do if they aren't re-vaccinated yearly.



QUOTE]

I agree with most of what Jeremy said (especially the part about my book that soon should get a Pulitzer) The only part I don't agree with is the 6 month thing with the immunity leaving. That would happen I think, if the tank was treated with copper or the fish and everything in it was quarantined for a long period of time. I believe that the parasites are alive and well in my tank (as I want them to be) reproducing in small numbers by grabbing on to fish and getting a quick meal of slime before jumping off to reproduce. Very rarely I will see a spot on a fish and it will be gone in a couple of days. I am hoping that is a live parasite and if it is, it is continuing to strengthen the immune system of the fish. So, if that is the case, the fish will always be immune as my fish seem to be.
We humans are covered in parasites but they stay on the outside of us because our immune system has no problem taking care of them. If we somehow were sterilized and we lost our parasitic load, we would no longer be immune to them and they could enter our bodies through our mouth and "other" areas. Soon after we die I am sure the parasites have a feast

 

[mcarroll]

I know tangs aren't generally schooling - that's a misconception.

The example I know best is the Bristlenoses...solitary detritavores. Probably the best-suited group for aquarium life. :)

But Tangs are reef-associated (at least the ones we care about) and I think they sleep socially when they take cover in the reef at night and while escaping predation. Plenty of vectors.

I think dilution, for our case, just changes the frequency not the nature of things.

If you have a population of suseptible fish - whether in the wild or in and aquarium - and they encounter The Evil Velvet™ I think the story would be the same. They don't fight it off. They give it to all their susceptible friends and susceptible neighbors. And that community is toast.

So what is it home about the aquarium?

It seems that fish must be continually stressed and even malnourished in one or more ways to be susceptible at the levels we see in so many home aquariums.

The thought that all your fish will become immune to the parasite, recover and then continue on not getting sick is a gamble, simply because of the environmental challenges posed in aquarium life.

I'm very curious about the disparity of how this applies so acutely to some reefers but not others.

We have example fishkeepers to study....quite a bit more on the tank wipeout side of the equation, but at least multiples on both sides.

We need more fish keepers to pick up a microscope (jewelers loupe, whatever) though – you are right about that, for sure!

Serious algae control freaks use microscopes all the time. Fish keepers seem, in general and by comparison, less serious. Where are all the 'scopes? Which is too bad for the fish....especially given their behavioral complexity. They could literally be thankful to us! :)

I know a loupe or 'scope will be a co-purchase along with my next fish.....but might be no time soon...no plans to add. Still would love to hear more experiences from people about making slides from their fish and what equipment they end up using to view them. Digital scopes are cheap, loupes are cheap....even decent microscopes appear to be available for around $100, which isn't cheap per se, but it won't break the bank. A small set of skills and more examples to follow seem to be all that's missing.

 

[Paul B]

I have loupes and a microscope. My Microscope is an antique and over 100 years old so I can only see old parasites, but I love the thing and use it all the time. I hatch brine shrimp every day and know each one by name.
This is an almost born clown gobi through my microscope.


And another one.


You can see my microscope to the left of my very cool, water cooled LED light for my algae scrubber.


I even have a state of the art projector. This was the cell phone video machine way before cell phones.

 

[mcarroll]

That projector looks like it's made of cast iron! LOL

 

[Paul B]

It is, just like my cell phone. :eek:

 

[mcarroll]

Even though it's targeted more at the aquaculture or zoo industries and we don't necessarily have to act like them, I like reading U. of Florida's stuff on fish care:

http://edis.ifas.ufl.edu/fa099
"Fish Health Management Considerations in Recirculating Aquaculture Systems—Part 1: Introduction and General Principles"

Any manager of fish health seeks to achieve two goals:

• to maximize immunocompetence in fish populations; and
  
  
• to reduce or eliminate potential pathogens (i.e., parasites, bacteria, viruses and fungi) in culture systems.

As a hobby, we are only just starting to focus on that first part. Notably, it anchor's the structure of their system. (Also notably, "Sampling & Treatment" are one topic.)

This intro is basically a really nice one-pager, so check it out.

We touch on most of it, but some things still get glossed over here....it's nice to see the concept laid out completely and named, etc. Apparently I do what is called "all in, all out stocking". Cool! :)

Here's a link to the whole Fish Health Management Considerations in Recirculating Aquaculture Systems series

 

[mcarroll]

Maybe that could have been in another thread...the immunocompetency part of their program is outside of this guide. ;)

 

[omykiss001]

One fact jumped out of the Wikipedia article on Histone (which I am reposting)
https://en.wikipedia.org/wiki/Histone#Conservation_across_species


This is also not the first time HLP-1 has popped into this discussion. (Hopefully I'm thinking of the right thread...perhaps it was not specifically in this thread.)

This may help:

https://scholar.google.com/scholar?q="hlp-1"+amyloodinium+|+cryptocaryon​

Results such as:

Histone-like proteins from fish are lethal to the parasitic dinoflagellate Amyloodinium ocellatum​

Ok I'll concede the point about activity of HLP to some eukaryotic parasites, I missed some of these studies in my pass of the literature last night it was late. There are some studies that suggest there is an inhibitory response from these proteins. However, I will caveat that the studies where I could get the full article and not just the abstract purification of HLP was not 100% and there were many contaminating proteins as evidenced the the electrophoretic gels they used to show the purity of their isolates. 2nd of the full article studies I could get most used concentrations at or above 100 ug/mL which is a fairly high concentration and they did not list what the concentrations found in the tissue directly normalized to mass or volume, so there could be inflation of the effect due to concentration differences. So, as a scientist I will concede there is some evidence of HLP like proteins that can have inhibitory action against some eukaryotic parasites and may be an important mechanism via innate immunity, but it is by far not the only one the organism uses. I haven't thought about HLPs since graduate school so I'm a bit rusty on the current research. However, it is clear the immune system innate and active are not 100% effective against these diseases even for healthy fish in the wild, otherwise parasites like these would be extinct as there would be no host they could infect and complete their life-cycle so there is always some that slip by, but infection numbers are low in the wild so no real harm comes to the host, but the immune system obviously even in healthy populations can't effectively eradicate the parasite either. Again pardon my miss on this one, I can admit when I did not do my due diligence and spoke out of line.

I think we also have to take into account innate defenses like these are really geared to slowing an infectious agent until the active immune response can be geared up. The immune cells, chemicals, and proteins that make up the innate response are the 1st line of defense, but not designed or good at fighting the larger battle if the infection takes hold, they just buy time and act and to communicate the nature of the pathogen to the active immune response which does the heavy fighting. The innate system can be easily overwhelmed if the infectious agent is highly virulent, and or encountered in large numbers. Much like what happens with A. ocellatum and C. irritans where they might start with a small number, but can very rapidly overwhelm the host especially in closed environment.

Most of my post was around the specific study you cited that they showed no evidence when the levels of HLP are lower, the fish is anymore compromised to clinical presentation of disease, they only used bacteria plate clearing assays to evaluate efficacy of response, no eukaryotic parasites were referenced. Their data actually showed that even when HLP levels were lower other anti-microbial molecules and proteins were elevated and the fish did not advance to a diseased state. The final conclusion of the paper was focused on using HLP level as a surrogate stress monitor (@Paul B sort of looking for your temp/blood pressure surrogate in finned critters). The authors did not draw any conclusions to specify they type of environment QT vs populated reef tank and if one or the other would cause stress or be more stressful. They actually used density of fish as the stress induction method so no other conclusions about environment being stressful can be inferred from this study. If I wanted to say what would cause HLP levels to drop it would be add the fish into a tank that had a high density of fish, so if the QT tank was 10 gallons and you added 5 fish to it, that might cause HLP levels to drop and indicate the fish are experiencing stress, same would most likely be true of a well stocked display system. Even if the fish are in a full reef tank they are still in a tank and if a well setup QT is causing stress to the animal how can you say the box with rocks and coral removes this stress. I don't think we can draw those conclusions nor do we have any controlled studies that indicate our fish are stress free in our display tanks no matter how wonderful we make the environment mimic their natural habitat. We only have our perception of what stress to a fish looks like, but little to no quantitative evidence any of our fish are immune compromised or that fish in QT are any more immune compromised, please don't confuse this to being naive immunologically to the disease. When I say quantitative I mean controlled studies. That was the only reason I suggested you evaluate what the authors of this paper were concluding as they made no reference to HLP being the critical innate immune response molecule, but just the contrary they actually found there are many others that do an equal if not better job to HLP with the assay methods they used and they made no reference to eukaryotic parasites and the efficacy against those.

When looking at the threads on R2R and other forums @Humblefish is correct seems many if not a majority of the my fish is sick threads are fish in a DT environment not a QT one and while I won't say there is anything conclusive about this it would suggest the QT environment is not the root cause of fish succumbing to disease or they somehow will be less healthy in the long run.

Again I strive to make my fish as healthy as possible and my QT environment as natural as possible I use a network of PVC that creates many caves of various size and crevasses that give the fish ways to swim and they don't have to be out in the open if they don't want to be. Also I don't keep my QT sterile by any means and allow as diverse of a microbial community as possible to be present, but made of a material I can use medication in if the need arises. I just would not throw in velvet, crypto or any other virulent pathogen into any system with fish anymore than I would expose my dog to distemper, heartworm etc. in the hopes he'll gain immunity to it. There is no reason a QT can't be a full reef, where only one fish is kept at a time. It just means if the need arises you have to catch the fish and move to an environment where medication can be used, or just see if they make it or not, this is still a method of quarantine.

Get them and keep em' healthy as possible I do believe in and I think the one item everyone in this discussion does not take issue with and really seems to be saying in one way or the other just differing viewpoint of what that means.

 

[mcarroll]

Just some more U of Florida stuff....a lot of this stuff should be our boilerplate.

FA156/FA156: Use of Vaccines in Finfish Aquaculture

An interesting link I found in there....want a vet that works with fish?
This place will supposedly help:
http://www.aquavetmed.info/​

Circular 919/FA005: Stress - Its Role in Fish Disease

A repost, but it seems like there's always something relevant in it. This goes to their calm appearance in QT that was brought up in an earlier post.

Resistance
An animal is able to adapt to stress for a finite period of time. During this period the animal may look and act normal, but is depleting energy reserves because of the extra requirements placed upon it.

I think resistance is a hazier concept than immunity (which is still a bit hazy itself), so this is a good one...it comes up all the time.

Disease Resistance
All fish do not get sick and die each time a disease outbreak occurs. There are many factors that affect how an individual responds to a potential pathogen. The pathogen (bacteria, parasite, or virus) must be capable of causing disease. The host (fish) must be in a susceptible state, and certain environmental conditions must be present for a disease outbreak to occur.

This one deserves to be in my signature line. If for no other reason than due to the number of people that avoid everything in here that doesn't involve a treatment or medication. But I'd never do that to everyone else...a quote will do. ;)

Prevention of Disease
Fish farm management should be designed to minimize stress on fish in order to decrease the occurrence of disease outbreaks. When disease outbreaks occur, the underlying cause of mortality should be identified, as well as underlying stress factors that may be compromising the natural survival mechanisms of the fish. Correction of stressors (i.e., poor water quality, excessive crowding, etc.) should precede or accompany disease treatments.

Stress compromises the fish's natural defenses so that it cannot effectively protect itself from invading pathogens. A disease treatment is an artificial way of slowing down the invading pathogen so that the fish has time to defend itself with an immune response. Any stress that adversely affects the ability of the fish to protect itself will result in an ongoing disease problem; as soon as the treatment wears off, the pathogen can build up its numbers and attack again. Rarely would a treatment result in total annihilation of an invading organism. Disease control is dependent upon the ability of the fish to overcome infection, as well as the efficacy of the chemical or antibiotic used.

 

[Humblefish]

This thread is enough to make my head hurt sometimes. :p

If you really want to help people avoid QT and rely upon immunity instead, why not come up with an easy to understand plan for people to follow? You all come up with a consensus protocol, and I'll even make it a sticky. :eek: What foods to feed, what supplements to use, what filtration to run, etc. etc. Basically, explain to our members how they should setup their tanks and what methods they should use to fight (or avoid) diseases naturally. All I ask is the information is presented in a straightforward manner that the average person can understand. ;)

Gentleman, I've thrown down the gauntlet. :D

 

[mcarroll]

Something like this is what I think we're working on! :) :) Coming to a consensus may be a matter unto itself. ;)

(I don't think doing away with QT's and meds altogether has to be or even should be part of the goal, either. It should/would be a natural side-effect.)

 

[sundog101]

I believe the disease problems in tanks are because of multiple factors. Not just a confined area, stress, and poor food, but everything. Basically fish are meant to be in the ocean. They weren't designed to live in aquariums. I think we should try to replicate the conditions and processes of the ocean as close as possible in our tanks. Now both methods can and do work, but only if done right. If you go the QT route, you have to QT everything. It can't be done halfway. Same thing with immunity, you have to actually keep your fish immune.
By the way, is Paul the only one brave enough to actually put ich in his tank?:D

 

[Paul B]

Sundog, I would sleep with ich if I thought it was good looking.
Humblefish. Your question is a good one but hard to explain in a few paragraphs (which is one reason I wrote a book) but I will try.
If you have a tank of quarantined fish it will be much harder to get them immune. As you know and I have said ad nausium a quarantined fish has a compromised immune system. That is fine as long as you keep quarantining. If you put an ich infected fish into a tank full of quarantined fish, guess what will happen? In my immune tank nothing will happen.
But if you start a tank with fish from the sea (which are already partially immune) and the tank is more natural than many tanks by not being very sterile. Maybe get some mud or at least use live rock, not dead rock. Put the fish in there and immediately and every day get some live bacteria into the fish from preferably live foods like worms or use clams. I realize many people can't get live foods or clams but I have problems dating Supermodels. That is not the Supermodels fault. I just can't do it even though I am very good looking and my Mother couldn't tell me apart from Tom Sellic. :eek: But the fish don't care that you can't get the proper food. It is what it is. If you live in Utah and the nearest LFS is in California, you are just out of luck and I don't know what to tell you. You need live bacteria. Commercially frozen food is normally irradiated to kill bacteria and parasites so that won't work. See if the supermarket has something from the sea that is fresh. I feed clams every day but I buy them live and freeze them. I am sure some of the bacteria will die, but not all of it.
Try to get live blackworms, I also feed them every day mainly for the bacteria but earthworms also work and they are everywhere. You can also raise whiteworms. These things are doable and not that hard. Use no foods that say sterilized, no flakes or pellets except for an emergency or as a supplement but not to often. You need no medications unless you buy a fish that is covered in parasites and you want to see if you can save it.
If you see some spots on one of your fish, don't go nuts. It is helping make the fish stronger and will go away. This only works if you are feeding as I said. No cheating with freeze dried worms or C Rations. I would imagine foods with probiotics "May" work but I would rather use real, live, natural bacteria. Of course if you have access to the sea, get some mud.
I will get back to this as I just made breakfast.:D

 

[shoelaceike]

Who says live bacteria in food helps the fish immune system? Most threads about ich are with tangs and in the wild all they consume is algae.

 

[Paul B]

I do. But I realize I don't carry much weight so it is in those links I posted at the beginning of this thread. Tangs eat bacteria covered live algae as well as all the creatures living on it. They also eat plankton and anything else they find that fits in their mouth. I have dove with tangs for over 40 years and they will eat anything. Cut up a sea urchin and see how they go crazy. (I don't do that any more as I feel it makes sea urchins hate me)

Who says live bacteria in food helps the fish immune system? Most threads about ich are with tangs and in the wild all they consume is algae.

Most threads about tangs and ich are also wrong.

 

[shoelaceike]

Interesting. I'm just thinking about other pets like dogs that would eat much more live bacteria in the wild yet dry kibble is just fine if not better

 

[Humblefish]

Humblefish. Your question is a good one but hard to explain in a few paragraphs (which is one reason I wrote a book) but I will try.

Maybe an article with a format similar to this: https://www.reef2reef.com/threads/how-to-quarantine.189815/

With sections discussing:

• How to setup your DT/what equipment to use. To assist with boosting immunity and/or eradicating disease in the DT.
• What foods to feed (live blackworms, clams, mussels, etc.)
• How to properly use fish oil in fish food
• Etc. etc.

You write it, I'll sticky it. :) People can decide for themselves which path to follow. Or maybe they will QT as I recommend, but do all the things in their DT that you suggest. Best of both worlds. :D

 

[Paul B]

I don't know anything about dogs. Dogfish and dogfaced puffers maybe, but not dogs.
Humble, I think I already answered all those questions above in that very informative paragraph as my theory is very simple but so many people try to make it complicated.
I will try to make it easier to understand and maybe post some pictures of Supermodels pointing to specific parts of the set up to highlight them. That's what they had when I was in the Army in Basic. Comic books of things to do with Supermodels doing them. I learned a lot.

In the meantime I still would like to see pictures of quarantined fish spawning, but not damsels. I would also like to see very old, quarantined fish, (preferably spawning or at least sexting)
I am curious about this and I will explain it after I see the pictures.
OK, now everyone with quarantined, spawning, non damsel fish, post some pictures.
There are 3318 pages of members on here which comes out to about a million members, give or take ten or so. I know there are thousands of tanks that are quarantined and have spawning fish.