Ich eradication vs. Ich management

[Paul B]

I loved it.

 

[Humblefish]

@omykiss001 Excellent observations! If you're a fish, it's easier for you to deal with parasites (and other nasties) when you have an entire ocean diluting them; not so easy when you and the nasties all live together in a tiny glass box. Although I've noticed those with very large systems (300+ gallons) seem to have an easier time of it.

Even still, fish in the ocean sometimes succumb to parasites, worms, bacterial diseases, viruses, etc. the same as they do in our aquariums. And that's just fine, because after all that's the cycle of life. But when I pay $50-100 for one of these little SOBs it's gonna live! Even if I have to cheat nature (by QT'ing) to ensure that happens.

 

[omykiss001]

@omykiss001 Excellent observations! If you're a fish, it's easier for you to deal with parasites (and other nasties) when you have an entire ocean diluting them; not so easy when you and the nasties all live together in a tiny glass box. Although I've noticed those with very large systems (300+ gallons) seem to have an easier time of it.

Even still, fish in the ocean sometimes succumb to parasites, worms, bacterial diseases, viruses, etc. the same as they do in our aquariums. And that's just fine, because after all that's the cycle of life. But when I pay $50-100 for one of these little SOBs it's gonna live! Even if I have to cheat nature (by QT'ing) to ensure that happens.

Absolutely agree I've taken responsibility for that life and I'm going to try to do everything I can to keep it kicking! I would add that we almost never get to see these "sick" fish in the wild as they become a tasty treat for a nearby predator long before they are appear ill to us

 

[Humblefish]

Absolutely agree I've taken responsibility for that life and I'm going to try to do everything I can to keep it kicking! I would add that we almost never get to see these "sick" fish in the wild as they become a tasty treat for a nearby predator long before they are appear ill to us

Excellent point! I sure hope you stick around. We could use someone with your education/background in the fish disease forum.

 

[4FordFamily]

Really like this article and I'd like to pose a couple of ideas regarding the data from this paper.

1st @4FordFamily probably has it right on that each species of fish has varying degrees of susceptibility to infection and extent of infection that will occur. The authors cite their data as well as those from several other studies they referenced that provide evidence not all fish are equal (this study mostly done with emperors and groupers). There are probably fish that have more active innate immune responses, and other species have morphological adaptations that make it difficult or impossible for the parasite to attach or feed on the host. Our own personal observations in our tanks also tend to support this as well given surgeon fish and some other species we tend to like also tend to be much more susceptible to infection and probably also become much more heavily infected when an outbreak occurs and suffer the greatest morbidity.

2nd the authors data also suggest the quality of water (quality indicated by dissolved nutrients in the water) and amount of water exchange have a big impact on infection rates in wild populations. Estuaries tend to be Eutrophic, where as sand bars and coral reef environments tend to be oligotrophic and ultraoligotrophic respectively. Here again the data presented by the authors indicated areas with higher nutrient loads (estuaries) and limited nutrient export in the ecosystem also have higher numbers of infected fish. To bring this back to our tanks. Systems that have been running for long periods and have good nutrient control and or fauna that quickly process the nutrient load may also have less mortality and morbidity if/when they have a exposure to crypto in that environment, my guess and only an educated guess, is the parasite does require some nutrients in the water to successfully complete its life-cycle and may explain why even if an infected fish is introduced the parasite can't get a foot hold in system where the nutrients are limiting. When I speak of nutrients there is probably more to the game than the ones we think of being nitrate and phosphate but also many other small organic molecules some of which may be required for parasite development and maturation that are consumed by specific microbes that may not colonize readily or quickly into our systems. This may be a reason why newer tanks that are still developing a mature microbial fauna may have a tougher time managing an outbreak. I know some will ask about higher levels of water movement being the cause as the author did mention that, but they also mentioned studies that show crypto tends to excyst on a circadian pattern (mostly at night). This parasite does have to swim to a host and given it is a single celled cilliate who can't cover lots of distance evolution more than likely has selected those parasites that swim when the chance of finding a host within it's range is greatest i.e. when the fish has bedded down for the night and is in close proximity to the substrate where excystment occurs.

In addition to this the data also clearly show that wild fish do tend to be infected and carry a "parasite load", but I think the key take away message given fish mostly rely on the innate immune response (see the article posted by PaulB in this thread) is the parasite load at any one time averages about 8-10 individual tomonts (Diggle and Lester, 1996; quote above) that the innate response can keep in check. Key thing to remember about the innate immune response that differs from the adaptive immune response that mammals use more heavily is the innate system can be overwhelmed much more easily. If you didn't already know the innate immune system uses macrophages, phagocytes and granulocytic cells, which you might think of as a police force roaming the body looking for invaders. If the riot is to large they can only attack parasites as fast as they can physically make contact with them and have to be in the same physical location to do so, where as the adaptive immune response involves T and B lymphocytes that take messages from the innate response and then produce very specific antibodies to that particular invader and then leave behind memory B cells that are always ready to mount a massive response to any reoccurrence, they can be thought of more like the air force and the heavy smart bombers. Once the message comes in the B-cells begin synthesizing large number of antibodies and these circulate through the blood so the immune cells themselves do not need to be in physical proximity to do their job and the invader in essence gets carpet bombed and the innate system them mops up the remains. Fish don't do as good with the air force, this part of their immune system is not well developed compared mammals.

Bottom line fish deal with Crypto in the wild, but they have manageable parasite loads their immune systems and physiology can handle. In the closed environments we provide it's probably pretty easy for this balance to turn and why the tenets of ich management are all targeting keeping the parasite as low as possible, which may still doom some fish who bed down where excystment occurs and have little in the way of natural resistance to the parasites themselves as noted by @4FordFamily and the Acanthurus genus which probably share morphology that makes them prone to infection. Ich management probably works because while you may not have success with these very susceptible species the parasite never gets to plague levels (i.e. concentration of free swimmers large enough) that cause massive infection and high mortality rates to a majority of fish species you keep it more in line with what is seen in the wild unless as noted by others an event occurs that shifts the balance to the parasites favor.

Sorry for the long winded comment to this thread, but found it to be a good read and being a biologist by trade I love that scholarly articles are used to support points, also found the articles quite informative given my specialty is mammalian immunology which does differ from that of our finned friends. Love to geek out on this stuff and share ideas

Thanks for your reply, it was a great read and only 1/3 of it went over my head!

Regarding nutrients and the prevalence or severity of infestation - could it be that excess nutrients weaken the immune response of the fish, rather than that the parasites themselves utilize the nutrients?

Just a thought, surely not as well thought out as yours! Thanks for your contribution!

 

[4FordFamily]

Excellent point! I sure hope you stick around. We could use someone with your education/background in the fish disease forum.

X3 we could all learn a lot from you (including how to count to 3 but nonetheless)

 

[omykiss001]

Excellent point! I sure hope you stick around. We could use someone with your education/background in the fish disease forum.

Happy to help where I can, I received great support in the forum while battling this parasite myself [emoji2]

 

[omykiss001]

Thanks for your reply, it was a great read and only 1/3 of it went over my head!

Regarding nutrients and the prevalence or severity of infestation - could it be that excess nutrients weaken the immune response of the fish, rather than that the parasites themselves utilize the nutrients?

Just a thought, surely not as well thought out as yours! Thanks for your contribution!

as I said it was just an educated guess, you could be very well correct the fish become more susceptible in those types of environments [emoji848]

I don't know of any studies that looked at water quality and fish immune function, also given their study site at the estuary of Brisbane river who knows what's upstream regarding pollution, kangaroo farms, and wombat sanctuaries there could be a chemical pollutant in the water, the study didn't reference if this was a pristine study site unaffected by human interaction or not.

 

[4FordFamily]

as I said it was just an educated guess, you could be very well correct the fish become more susceptible in those types of environments [emoji848]

I don't know of any studies that looked at water quality and fish immune function, also given their study site at the estuary of Brisbane river who knows what's upstream regarding pollution, kangaroo farms, and wombat sanctuaries there could be a chemical pollutant in the water, the study didn't reference if this was a pristine study site unaffected by human interaction or not.

That's fascinating. Glad we have someone to summarize all of these studies lol. I can talk KPI, value chain, finance, and economics but your realm is largely like reading Korean. The diverse group of folks on this forum make it so great!

 

[Paul B]

No matter what we do. Virtually all of the fish we put in our tanks should die of old age. (or jumping out) If they are not, we are doing something wrong. Just my opinion of course

 

[mcarroll]

From this abstract:
http://europepmc.org/abstract/med/9270832

Environmental stress factors which influence fish immune (and likely many other physiological) functions can be divided into two broad, but not mutually exclusive, categories, namely those which occur naturally and those which are artificial. Natural environmental stress factors include season, temperature, salinity and photoperiod as well as social stress factors such as crowding and hierarchy. In general, artificial environmental stress factors are man made, and mainly involve pollutants such as acid rain, heavy metals and organic compounds. The available data indicate that regardless of which immune parameters are assessed, both natural and artificial environmental stress factors appear to suppress immune functions. Of the numerous environmental stress factors considered, pollutants, handling/confinement and low temperature are probably the best studied forms in fish. All three forms of stress factors have been shown to suppress components of both the innate (non-specific) and adaptive arms of the immune system. Since immune responses which protect against invading pathogens frequently involve interactions between both the innate and adaptive arms of the immune system, it seems reasonable to conclude that either acute or chronic exposure to stress factors may predispose fish to infectious diseases.

 

[mcarroll]

Ew....I should have summarized that. Too big a block of text to even see it all via the website inerface. (Fine on phone app.)

Here's the nutshell version, paraphrased:

All forms of stress, from overstocking to malnourishment to environment, may predispose a fish to infectious diseases.

• When a fish is placed in cramped quarters, you are cramping his immune system.
• When a fish is dosed with medicine prophylactically, you are cramping their immune system.
• When a fish is denied adequate nutrition, you are cramping their immune system.
• When a fish is exposed to over-agressive tankmates, you are cramping their immune system.

This is why QT'ing apparently-healthy fish is generally a bad idea.

You are actually doing more than cramping their immune system...and that's not a comprehensive list of "why's", but I hope it's enough to make the point: Keep the healthy fish in the healthy tank - filter it with a diatom filter if you must. But don't "kneecap" your healthy fish's immune system and throw him in a little tank with an actual sick fish. Even if he was at some risk, you just make it worse by doing this.

 

[Humblefish]

This is why QT'ing apparently-healthy fish is generally a bad idea.

How does one tell if a fish is "apparently-healthy"? This forum is filled with example of folks who buy fish that look/eat great at the LFS and then BAM! wipe out their DT with velvet.

 

[Paul B]

Experience.

 

[Humblefish]

Experience.

Due to the high turnover rate, most people in this hobby will always lack that. And then you have to consider with the growing popularity of Internet buying, a fish is sometimes bought sight unseen. A good QT protects you from both inexperience and the unknown.

Even you have stated you've bought a new fish, it develops white spots and dies. Same has happened to me. So apparently the trained eye isn't always enough.

 

[saltyfilmfolks]

Experience.

A good QT

As an Intermediate(if I may compliment myself) the hardest thing to consider is what is a good quarantine from experience(mine or reading yours)
I'm really hesitant right now to buy a fish.
Paul is correct on soo many levels about putting a fish in a tiny box with a pvc elbow immune systems and bacteria.
Dr Fish your absolutely correct on making sure you dont introduce disease or alleviate the disease from a stressed fish . And as I read further into your writing, your ideology is much more open and holistic than i think people get.

Im blessed to have a dozen places to buy fish and corals(more if you dont mind Craigslist and dark alleys)
From the wisdom I have gained from Both of you and Robert and others, it seems you really have to know what the LFS is doing with the fish too.
Of them I know 3 very well.
One has a copper wall. so I should have QT with little bacterial load(ie new non established) and slowly acclimate to my dt bacteria and no further meds.
One no medication, so established qt and freshwater dip maybe depending on species light meds.
and one warehouse where you never know. Its been in with other poorly chosen tank mates and is a total stress mess. So fish beer and a copy of Playfish magazine.
At that point the dark alley fish is the easier really.
And all the above make it a coin toss. Is that crazy? I cant think of any one better to ask.

its really been the focus of my study here recently. I hate losing fish.

 

[mcarroll]

How does one tell if a fish is "apparently-healthy"? This forum is filled with example of folks who buy fish that look/eat great at the LFS and then BAM! wipe out their DT with velvet.

Experience.

If you can't select a healthy fish, you need to ask the store where you're buying it. And yes that means you have to be able to trust them. And yes that means you have to be able to know them.

And if that describes you, you really shouldn't be shopping for fish online.

I'm dubious about buying fish online in general. To me it does not seem like it is possible to make a responsible purchase when you cannot see the fish or the person selling it to you. I mean if you can't trust the local fish store and your own eyeballs, how can you trust this?

Due to the high turnover rate, most people in this hobby will always lack that. And then you have to consider with the growing popularity of Internet buying, a fish is sometimes bought sight unseen. A good QT protects you from both inexperience and the unknown.

Even you have stated you've bought a new fish, it develops white spots and dies. Same has happened to me. So apparently the trained eye isn't always enough.

Some fish are not savable. It doesn't matter if you QT it doesn't matter if you bless them.

All I am saying is that it doesn't make sense to take a fish that appears healthy and stick it in a small box with a sick fish.

If you have no capability of assessing whether a fish is healthy or not then no amount of QT or medicine is going to help.

 

[mcarroll]

(My implication there, in case it wasn't too clear, is that we do have the capability to assess whether a fish is healthy in most cases. And I do think some QT and some medicine will help in some cases. I'm not anti. [emoji106])

 

[4FordFamily]

I agree but yet the vast majority of fish purchased in this hobby do not make it to old age. I would venture to guess its at least 80%. Again, that's a guess.

So clearly our practices are lacking. I for one have had significantly superior results treating all incoming fish and quarantining them. This does not mean the alternative cannot be done but with some species - it is almost as if it cannot be done.

 

[Humblefish]

And all the above make it a coin toss. Is that crazy? I cant think of any one better to ask.

its really been the focus of my study here recently. I hate losing fish.

I'm not sure if this answers your question, but you always have the option of just passively observing in QT. And it doesn't have to be in a tiny box with PVC elbows. Setup a frag tank or a miniature version of your DT. Just use less rock so the fish can be caught. Observe in there and move to a treatment tank if symptoms of a disease arise. Even if you don't catch symptoms of ich/flukes, 1 month of passive observation will save your DT from velvet, brook and other "tank killers". It may not be the best QT option (according to me) but it's better than nothing.

If you can't select a healthy fish, you need to ask the store where you're buying it. And yes that means you have to be able to trust them. And yes that means you have to be able to know them.

And if that describes you, you really shouldn't be shopping for fish online.

I'm dubious about buying fish online in general. To me it does not seem like it is possible to make a responsible purchase when you cannot see the fish or the person selling it to you. I mean if you can't trust the local fish store and your own eyeballs, how can you trust this?

I don't trust most LFS owners/employees any further than I can throw them. Seriously though, you can't take the advice of someone wanting to sell you something. You have to choose for yourself. Back when I bought fish for my own pleasure, I had a much better success rate buying online than at a LFS.

All I am saying is that it doesn't make sense to take a fish that appears healthy and stick it in a small box with a sick fish.

Those who are patient always have the option of QT'ing their fish one at a time.

I agree but yet the vast majority of fish purchased in this hobby do not make it to old age. I would venture to guess its at least 80%. Again, that's a guess.

An estimated 70-90% of collected fish don't survive long enough to make it to a LFS.