Common Misconceptions In the Hobby

[EvilE]

That's Jeff Garcia's wife!

[capn_hylinur]

Heres a link to another thread---claiming all fish in the wild carry ich---if this isn't misconception for the masses then it is misconcenption for me

http://archive.reefcentral.com/forum...5&pagenumber=2

[Paul B]

I believe that many or possably, most fish in the sea have ich just as all humans carry mites. If you look at a microscope drop of seawater you will see that there is not much free room in there with much of it taken up by tiny life.
Ich in the see is totally inocuous and does not harm anything.
It is only when it is confined to a tank does it multiply to proportions where it can affect fish. Ich itself does not directly harm fish much. The sheer number of paracites infecting the gills interfere with the transfer of oxygen along with the scar tissue they create there. Tiny paracites on the scales don't bother the fish at all but if you see them there it is a sure sign that the gills are infected.

[greenbean36191]

Studies in the wild show that it's not ubiquitous, but fairly common with somewhere between 1/3 and 3/4 of fish tested carrying it. However, like Paul said, the parasite loads are small at between 2-15 parasites per fish.

[greenbean36191]

And another ich myth while I'm at it: keeping the salinity in the 1.021 range will keep fish healthier. There is absolutely no evidence of this. I suspect it's based on the false assumption that if fairly short stints at really low salinities hurt parasites then long term exposure at slightly low salinities will get them too. One of the same studies that looked at the overall prevalence of ich in the wild also compared rates between estuarian and oceanic areas. The infection rates were consistently higher in the estuaries.

[Ninong]

Originally posted by greenbean36191
Studies in the wild show that it's not ubiquitous, but fairly common with somewhere between 1/3 and 3/4 of fish tested carrying it. However, like Paul said, the parasite loads are small at between 2-15 parasites per fish.

And it may be geographically related because the incidence of C. irritans appears to vary widely with some studies showing very few, if any, infected fish and other studies showing low levels of infestation to be fairly common.

Study finding few, if any, infected fish in Puerto Rico: Bunkley-Williams L. and Williams E.H. 1994. Disease caused by Trichodina spheroidesi and Cryptocaryon irritans (Ciliophora) in wild coral reef fishes. Journal of Aquatic Animal Health 6:360-361.

Diggles and Lester found low levels of infestation were fairly common in southern Queensland:

Diggles B.K. and Lester R.J. 1996. Influence of temperature and host species on the development of Cryptocaryon irritans. J Parasitol 82:45-51.

Diggles B.K. and Lester R.J. 1996. Variation in the development of two isolates of Cryptocaryon irritans. J Parasitol 82:384-388.

There are older studies that also seem to confirm that distribution varies geographically.

[Ninong]

Originally posted by greenbean36191
And another ich myth while I'm at it: keeping the salinity in the 1.021 range will keep fish healthier. There is absolutely no evidence of this. I suspect it's based on the false assumption that if fairly short stints at really low salinities hurt parasites then long term exposure at slightly low salinities will get them too. One of the same studies that looked at the overall prevalence of ich in the wild also compared rates between estuarian and oceanic areas. The infection rates were consistently higher in the estuaries.

I suspect it may also be based on the recommendation by Delbeek and Sprung (1994) in The Reef Aquarium, Volume 1 that lowering the specific gravity to 1.017 is effective in controlling outbreaks of C. irritans. It isn't. Tomonts can survive salinities as low as 15 ppt (1.011 SG) according to studies done by Colorni, 1985.

And if you have any invertebrates in your tank, then I think it would be unwise to follow this "advice."

P.S. -- This particular bit of "advice" from these two authors has been a topic of discussion for years. I haven't come across anything online from either one of these gentlemen either retracting or clarifying their original recommendation.

[capn_hylinur]

Originally posted by Ninong
I suspect it may also be based on the recommendation by Delbeek and Sprung (1994) in The Reef Aquarium, Volume 1 that lowering the specific gravity to 1.017 is effective in controlling outbreaks of C. irritans. It isn't. Tomonts can survive salinities as low as 15 ppt (1.011 SG) according to studies done by Colorni, 1985.

And if you have any invertebrates in your tank, then I think it would be unwise to follow this "advice."

P.S. -- This particular bit of "advice" from these two authors has been a topic of discussion for years. I haven't come across anything online from either one of these gentlemen either retracting or clarifying their original recommendation.

so this is the reason for hyposalinating to low levels like 1.009?

[capn_hylinur]

Originally posted by greenbean36191
Studies in the wild show that it's not ubiquitous, but fairly common with somewhere between 1/3 and 3/4 of fish tested carrying it. However, like Paul said, the parasite loads are small at between 2-15 parasites per fish.

the other thread I was referring to stated all fish caught carry ich----do you think that is too broad a generalization here?



quote: my LFS says that all wild-caught fish have it. It's just inherent, with cysts essentially hanging out in the fish's mucus until a period of stress arises. This is why some fish, like the tangs - which are easily stressed, are more prone to it. Their immune systems just can't keep it at bay. Makes sense to me.

I am going to continue the 5-nitroimidazole treatment of my display tank with a lot of water changes, and run a copper-containing QT henceforth.

[Ninong]

Originally posted by capn_hylinur
so this is the reason for hyposalinating to low levels like 1.009?

Yes. A specific gravity of 1.009 would effectively kill off the tomonts.

However, there are a few recorded instances of new strains of Cryptocaryon irritans that have been discovered in estuaries with much lower salinities. Since few of us are likely to acquire fish that were collected from these locations, we should be safe with the 1.009 SG recommendation.

[Paul B]

quote: my LFS says that all wild-caught fish have it. It's just inherent, with cysts essentially hanging out in the fish's mucus until a period of stress arises. This is why some fish, like the tangs - which are easily stressed, are more prone to it. Their immune systems just can't keep it at bay. Makes sense to me.

Ich does not hang out on fish until stress causes it to infect but ich can live happily in your tank (as it does in mine). The paracites hatch depending on temperature, and actively move around looking for another (or the same) fish to complete their life cycle on. If the fish are very healthy and for reasons not fully understood (even though many people think the life cycle of this paracite is well understood) you can have ich in your tank continousely for years, or decades if you keep adding fish, without having an outbreak.
Or of course, you can quarantine and keep ich out of your tank.
I now have a bottom dwelling goby that has ich. He is in my reef with about 15 other fish which do not have it. This particular gobi has always had a problem competing with other fish for food and he peridocally gets very thin and floats at the surface near death. At this point he becomes covered in paracites. I rescued him and transfered him to another tank where he is fed well and he will recover with no treatment. This has happened to this fish three times already and it has happened to other fish that I keep. About 8 months ago my hippo tang was also covered in ich as was my fire clown. When the stressful event is removed and the fish is fed well a diet that is natural to it, it recovers.
I do not know why this happens but it has been happening for over 25 years. There is obviousely ich in my tank but it never appears until the fish are either dying from an accident like jumping out, heater malfunction or an accidental poisoning.
In any event, when the fish are in breeding condition (which captive fish rarely are) they never exhibit ich (in my tank anwway)
I don't care how many experts study ich and report on it's life cycle. There is something about this paracite that is not completely understood. It certainly can live in a tank and not be a problem although in many tanks it is fatal almost always if not treated. I hope someday we figure this out along with that hair algae and cyano problem, two more pet peeves of mine
Have a great day.
And sorry, experts

[Ninong]

Originally posted by Paul B
...ich can live happily in your tank (as it does in mine). The paracites hatch depending on temperature, and actively move around looking for another (or the same) fish to complete their life cycle on. If the fish are very healthy and for reasons not fully understood (even though many people think the life cycle of this paracite is well understood) you can have ich in your tank continousely for years, or decades if you keep adding fish, without having an outbreak.

The operative phrase is "if you keep adding fish."

You cannot maintain a viable population of Cryptocaryon irritans without adding new infected fish to your system on a regular basis. Even if you say that a few of the fish in your system have very low levels of infestation that aren't noticeable and go undetected and are thus maintaining the parasite's life cycle, it will die off within 12 months due to senescence.

The life cycle of C. irritans has been extensively studied at this point. Burgess and Matthews (1994) were attempting to maintain a viable population of C. irritans which could be used in later studies. To maintain the parasite populations, they needed host fish in order for the trophonts to feed and continue the life cycle. Each host fish was only used once in a process of serial transition such that none of the hosts would die or develop an immunity. While the procedure worked very well and enabled them to maintain populations for some time, the viability of the populations decreased with time and none of the 7 isolates they used survived more than 34 cycles, around 10 to 11 months. They suggest this is due to senescence and aging in cell lines is well recognised in Ciliophora.

The presence of aging cell lines in C. irritans suggests that an aquarium that has been running for longer than 12 months without any additions is unlikely to have any surviving "Ich" parasites. Here.

[Philwd]

Ninong - I found a different study claiming that after 2 years the ich lines were still going strong. I posted it a while back on other ich threads. Maybe different strains. I don't have the link handy.

[Ninong]

Originally posted by Philwd
Ninong - I found a different study claiming that after 2 years the ich lines were still going strong. I posted it a while back on other ich threads. Maybe different strains. I don't have the link handy.

I just googled "Cryptocaryon irritans senescence" and came up with the following.

A Standardized Method for the In vivo Maintenance of Cryptocaryon irritans (Ciliophora) Using the … - all 3 versions »
PJ Burgess, RA Matthews - The Journal of Parasitology, 1994 - JSTOR
... here was associated with a de- cline in viability, suggestive of senescence. ... Hypersaline
and chemical control of Cryptocaryon irritans in red snapper, Lutjanus ...
Cited by 11 - Related Articles - Web Search - BL Direct

Two year study on the infectivity of Ichthyophthirius multifiliis in channel catfish Ictalurus … - all 4 versions »
DH Xu, PH Klesius - Diseases of Aquatic Organisms, 2004 - int-res.com
... fac- tors may be considered when addressing the senescence of the ... HW, Dawe DL (1995)
Ichthyophthirius multifiliis and Cryptocaryon irritans (Phylum Ciliophora ...
Cited by 2 - Related Articles - Web Search - BL Direct

The I-antigens of Ichthyophthirius multifiliis are GPI-Anchored Proteins - all 6 versions »
TG CLARK, YAN GAO, J GAERTIG, X WANG, G CHENG - The Journal of Eukaryotic Microbiology - bioone.org
... However, the G1 isolate was lost due to senescence (Clark, Lin, and Dickerson 1995 ...
Ichthyophthirius multifiliis and Cryptocaryon irritans (Phylum Ciliophora). ...
Cited by 16 - Related Articles - Web Search - BL Direct

The first reference is the one I'm citing. Are you talking about the second reference? If so, I'm not familiar with that study and I can't access it online. Did it cover C. irritans as well as Ichthyophthirius multifiliis?

P.S. -- As you probably know, C. irritans is only distantly related to I. multifilius in spite of their similar life cycles.

[greenbean36191]

The only mention of Cryptocaryon in the last two is the title of one of the references cited (the same reference in both papers).

[Ninong]

Originally posted by greenbean36191
The only mention of Cryptocaryon in the last two is the title of one of the references cited (the same reference in both papers).

Does that mean you're familiar with them and they don't cover C. irritans senescence? Maybe they just studied I. multifilius? Can you access them online?

[greenbean36191]

Yes, to all of those questions.

Here's the paper Philwd posted in an earlier thread:
Yoshinaga, T. & H.W. Dickerson. 1994. "Laboratory Propagation of Cryptocaryon irritans on a Saltwater-Adapted Poecilia Hybrid, the Black Molly" Journal of Aquatic Animal Health 6:197-201, 1994.

[Paul B]

The operative phrase is "if you keep adding fish."

Ninong, thats why I purposely added that line.
I know all about Burgess's study of ich and I am not sure if I agree with him or disagree since I have not done scientific studies myself. In any case it has no bearing on my above statement. Most people add something at least once a year.
I personally add animals all the time, some from stores and a lot from the sea. For some reason, sometimes, ich can live in a tank full of fish without causing harm. I have proof of that but I don't know why. I wish I did.
I am fairly certain that no one else knows why either.
I have been following Burgess work for many years, since he was a fresh water "Expert"
Take care.
Paul

[capn_hylinur]

Originally posted by Paul B
Ninong, thats why I purposely added that line.
I know all about Burgess's study of ich and I am not sure if I agree with him or disagree since I have not done scientific studies myself. In any case it has no bearing on my above statement. Most people add something at least once a year.
I personally add animals all the time, some from stores and a lot from the sea. For some reason, sometimes, ich can live in a tank full of fish without causing harm. I have proof of that but I don't know why. I wish I did.
I am fairly certain that no one else knows why either.
I have been following Burgess work for many years, since he was a fresh water "Expert"
Take care.
Paul

don't you think alot of that can depend on diet/vitamins etc and lack of stress for the fish?

[Paul B]

don't you think alot of that can depend on diet/vitamins etc and lack of stress for the fish?

Yes Capt. I do. I also think there is something besides these three things. It may be that fish in breeding condition have some sort of immunity from the paracite. Fish in a store are very susepticle to ich probably from all of the things you mention. I am sure stress plays a large part. Confined fish start out with a disadvantage no matter how well we feed them or how many vitamins we provide. They know they are confined and they don't like it. Thats why you never see adult fish in 12" of water as we usually keep them. I have seen royal gramma's in 120 feet of water, they are there because they want to be deep. If you released our fish back to the sea the first thing they will do is head for deep water, they just feel safer there. Tangs or so called, "Ich magnets" will immediately look for their kind because they are schooling fish and are almost never seen alone.
Our fish are stressed no matter what we do but if they exhibit breeding behavior they may have gotten over their fear and therefore their stress. If your fish are not exhibiting breeding behavior they are not as healthy as you think they are. Fish do two things all the time, eat and breed. Even a lone clownfish will clean off a nesting place and chase other fish away, gobies will do the same thing. Tangs will not do this for a few reasons, they don't build nests and they will be too stressed in a tank without a school thats why they are "Ich magnets" It is our fault not theirs.
I don't know if stress is the only factor or what role it plays, I also do not know if as some authors suggest, a fish can build up an immunity to ich. It seems to me that would be like having an immunity to bullets as these paracites inhabit the outside of the fish. As far as I know we humans can't build up an immunity to mosquetoes or bee stings, we may have an immunity to the venem but paracites do not kill the host with venem or even sucking the blood, they kill by blocking the gills with their bodies.
Fish stress is not an easy thing to study. Human stress is not too easy and we can talk.

[greenbean36191]

Developing immunity to ich is nothing at all like developing immunity to bullets or mosquitoes. Despite their proximity to the surface of the skin, these are internal parasites. It's more like developing an immunity to traveler's diarrhea. There are many other cases of animals developing immunity to internal macroparasites, including other fish parasites, so the idea that immunity can be acquired doesn't seem far fetched at all IMO.

I think Burgess and Matthews demonstrated pretty well that fish can develop immunity to ich. 30-80% of previously exposed fish showing no parasites vs. 0% of naive fish is pretty significant. They also showed extremely significant differences in the parasite loads. It's hard to ask for an experiment that gives more cut and dry results than that.

[capn_hylinur]

Originally posted by Paul B
Yes Capt. I do. I also think there is something besides these three things. It may be that fish in breeding condition have some sort of immunity from the paracite. Fish in a store are very susepticle to ich probably from all of the things you mention. I am sure stress plays a large part. Confined fish start out with a disadvantage no matter how well we feed them or how many vitamins we provide. They know they are confined and they don't like it. Thats why you never see adult fish in 12" of water as we usually keep them. I have seen royal gramma's in 120 feet of water, they are there because they want to be deep. If you released our fish back to the sea the first thing they will do is head for deep water, they just feel safer there. Tangs or so called, "Ich magnets" will immediately look for their kind because they are schooling fish and are almost never seen alone.
Our fish are stressed no matter what we do but if they exhibit breeding behavior they may have gotten over their fear and therefore their stress. If your fish are not exhibiting breeding behavior they are not as healthy as you think they are. Fish do two things all the time, eat and breed. Even a lone clownfish will clean off a nesting place and chase other fish away, gobies will do the same thing. Tangs will not do this for a few reasons, they don't build nests and they will be too stressed in a tank without a school thats why they are "Ich magnets" It is our fault not theirs.
I don't know if stress is the only factor or what role it plays, I also do not know if as some authors suggest, a fish can build up an immunity to ich. It seems to me that would be like having an immunity to bullets as these paracites inhabit the outside of the fish. As far as I know we humans can't build up an immunity to mosquetoes or bee stings, we may have an immunity to the venem but paracites do not kill the host with venem or even sucking the blood, they kill by blocking the gills with their bodies.
Fish stress is not an easy thing to study. Human stress is not too easy and we can talk.

thanks for the detailed answers Paul--as always it is welcomed and appreciated.
I understand what you are saying about the fish being understressed because we are not totally matching real reef conditions for them.
However how much do you feel the conception of adaptation factors into this. I know earlier in this thread Greenbean has suggested that marine fish can adapt to fluctuations in temperature etc.

Greenbean---I am not quoting your here--its just my take on what you wrote

I think it was mentioned around the idea that we can actually teach fish to be less adapatable to fluctuations by maintaining systems that have very little fluctuations---which is acutally not the norm for real reefs.

That said can we not expect that our fish could adapt to differences in water depth from the real reef.
I keep my numbers on the high side with fish--and have three tangs---would the larger number of fish also help the tangs with the stress of not having schools?

I am wondering if your example of the gramma has other factors rather then depth---at 120 feet --are the temp and oxygen levels not going to play a big part?

These are not challenges--rather meaningful questions---I appreciate being able to discuss things with such experienced and knowledgeable people like you and greenbean(not to mention the many others)

[capn_hylinur]

Originally posted by greenbean36191
Developing immunity to ich is nothing at all like developing immunity to bullets or mosquitoes. Despite their proximity to the surface of the skin, these are internal parasites. It's more like developing an immunity to traveler's diarrhea. There are many other cases of animals developing immunity to internal macroparasites, including other fish parasites, so the idea that immunity can be acquired doesn't seem far fetched at all IMO.

I think Burgess and Matthews demonstrated pretty well that fish can develop immunity to ich. 30-80% of previously exposed fish showing no parasites vs. 0% of naive fish is pretty significant. They also showed extremely significant differences in the parasite loads. It's hard to ask for an experiment that gives more cut and dry results than that.

Accepting this could have a large impact on the use of qt tanks----why qt for ich if you build up the immunites of your fish in the main tank.
I am not considering other practical uses for qt tanks here like getting more difficult fish to eat, treating with chemicals etc etc)

[greenbean36191]

Accepting this could have a large impact on the use of qt tanks----why qt for ich if you build up the immunites of your fish in the main tank. I am not considering other practical uses for qt tanks here like getting more difficult fish to eat, treating with chemicals etc etc)

Because the immunity is not total for many fish, meaning they can still harbor the parasite and the odds of all fish in a tank developing total immunity is low. Any future changes can still allow population growth of the parasite, causing renewed outbreak, even in fish with resistance. The immunological memory also isn't permanent, so even fish that develop immunity at one point can become infected again if they go long enough without exposure. You could in theory eradicate it from the tank through immunity or at least keep it at very low levels only to have it come back on with the addition of a new fish.

[capn_hylinur]

such is life