Literature to support that 72 day number for fallow tanks to eradicatde crypto

[Joules]

Folks,
I keep debating this in my head.
The recommendation is 72 days fallow to make sure every last encysted tomont hatches. Was that number measured in a fallow tank, or in a tank housing fish....seems like it would have to be fallow to conduct this study without introduction of new encysted tomonts, and that the study would've been done in a fishless laboratory tank.

However, what about the presence of fish hormones? Are the outliers potentially waiting as long as possible (72 days) because there are no fish present? If so, then we could expect the parasite to be eradicated earlier in a tank that is medicated while housing fish.

I just bought the oft cited journal article by Colorni and Burgess, 1998, and reviewed it. Based on the faith placed in this reference, I was expecting something with experimental details, but really, it just states the 72 day maximum time to hatching.....that's what everybody is citing.

It seems the original citation of that number references back to a graduate thesis by Colorni in 1992 that is sitting on a shelf in Hebrew University....I haven't been able to access it.

I was wondering if anybody out there has a copy of the experimental section that they could send me?

 

[alprazo]

I'm pretty sure I have it. I know I posted somewhere here about the study. I will look. If I remember correctly, it was a cold water strain from Vietnam. I could be confusing articles though.

 

[snorvich]

Colorni and Burgess 1997; Dickerson 2006; Yambot 2003

 

[ThRoewer]

CRYPTOCARYON IRRITANS, TRANSMISSION AND IMMUNE RESPONSE IN THE MULLET CHELON LABROSUS
Burgess, 1992

Characterization of Cryptocaryon irritans, a parasite isolated from marine fishes in Taiwan
Apolinario V. Yambot, Yen-Ling Song,*, Hung-Hung Sung, 2003

If someone has more links to publications, please post them.

 

[Joules]

Thanks...the Burgess 1992 was perfect, thought it reported longest time to excystment of 35 days in one of five isolates.

So, the answer is.....fallow conditions at 75-78 F.

Specifically, this was natural sea water from Plymouth deep channel in the uk. Water is pumped to shore, shipped by tanker, stored in subterranean tanks, and finally, passed through 0.2 um filters to sterilize.

Interestingly, they sometime washed the cysts with tap water if there were signs of contamination. While exposure to tap water was "less than one minute" it had no effect on cyst viability or development.

So....has anybody ever heard of faster release in the presence of fish?

 

[ThRoewer]

My concern with Burgess's study is regarding his immunity findings.
It was done with a single, non-territorial fish species (Chelon labrosusso) from the Atlantic and Mediterranean and 8 (9) strains of Cryptocaryon.

I would be very careful with generalizing it's findings about immunity towards highly territorial reef fish (my own observations speak against this generalization).

"... An acquired protective immune response developed in host mullet within 14 days after exposure to sub-lethal infection. The degree of immunity appeared to relate to infection dose, and was not fully protective in all fish. Protection persisted for six months after infection and appeared specific to C.irritans. ..."

ALL fish were individuals of the same above mentioned species, not of different species as is often assumed around here.

Also the six month period is without the presence of the parasite - if parasites are present or the fish maintains a low level infection I would suspect the immunity to persist longer.


As for the 72 days - that may or may not be the maximum certain Cryptocaryon strains can lay dormant. I've gotten pretty convincing reports that in certain regions (East African reefs) widespread Cryptocaryon outbreaks coincide with the monsoon season, which may or may not point to longer dormant periods and wake-up triggers like changes in salinity, oxygen levels, REDOX potential,...

But even the observed 72 days are for sure an extreme you shouldn't expect every time and with every strain.

I personally feel the 6 weeks fallow you need for eradicating Amyloodinium and Brooklynella (both of much greater concern) should in most cases also be fine for Cryptocaryon. For small and manageable fish populations of highly territorial fish I wouldn't go beyond that. Should I get a Cryptocaryon outbreak after that I can still repeat it with the 11 weeks.

If you plan on adding fish that are highly susceptible to Cryptocaryon infections (among others pretty much all surgeon and butterfly fish) you probably better err on the side of caution and go fallow for 11 full weeks and execute a rigorous quarantine and preventive treatment protocol on all fish before adding them to the tank.

Now, if you plan to set up a huge tank with too many fish to catch and treat I would be extra, extra careful and rather start out fallow for a year (which is actually a good period to get a large tank properly cycled) before adding the first fish (well quarantined and with at least 2 rounds of TTM).

 

[Joules]

Interesting ThReower...unfortunately, I made the failure to quarantine mistake over a year ago and have been fighting crypt ever since with various courses of hospital tank treatment, DT treatment, CP, hypo, medicated foods....and most recently quinine sulfate. I have never seen anything that has made me believe my tangs acquired any form of immunity, which is consistent with your thoughts. It seems to have worked (fingers crossed) even with only 24 days treatment but I continue to check for signs of illness twice a day. I'm mostly surprised, because it seems pretty clear that no fish-safe drug kills cysts, and 24 days seems too short based on recommended fallow times.


I intended to treat longer, but needed to end the treatment early due to apparent toxicity, which led to the death of a flame angel (male, the female survived) and fathead anthias, which both stopped eating and started looking shy and a bit ragged in the fins around 18-20 days at 15 ppm quinine. My purple tang had shown such extreme signs of toxicity after only 10 days (rapid breathing, hiding, not eating) that I removed him from the DT into a drug-free HT by himself. I returned him to the DT about a week after I reduced the quinine to 1 ppm using water changes and carbon. However, I thought I many have seen a spot on him as I was returning him, so I gave him a bath in 20 ppm quinine and paraguard for 2 hours, then upped the quinine in the DT to 12 ppm. Other fish I had in the tank include a kole tang, pbt, and yellow wrasse (the one people refer to as "yellow coris." None of these ever showed signs of toxicity. I had previously had a sailfin that behaved similarly to the purple tang with high levels of degraded CP in the water, which leads me to believe that the zebrasomas are particularly sensitive to quinolines.

After 4 days, he began showing signs of toxicity, so drug was removed again.
It's been a week and no spots on anybody (including a pbt).

(As a side note, I am a practicing scientist and have access to a tool that lets me accurately measure drug concentrations. My tank evolved the ability to detoxify chloroquine, presumably through a micro-organism. Quinine is not detoxified by whatever is chewing up the CP, and the concentration slowly decreased from 15 ppm to 14 ppm over 24 days, even with the skimmer on. That said, I see no reason why a tank couldn't evolve similar resistance to quinine and leave chloroquine untouched instead.....as they say, "Life finds a way.")

 

[snorvich]

(As a side note, I am a practicing scientist and have access to a tool that lets me accurately measure drug concentrations. My tank evolved the ability to detoxify chloroquine, presumably through a micro-organism. Quinine is not detoxified by whatever is chewing up the CP, and the concentration slowly decreased from 15 ppm to 14 ppm over 24 days, even with the skimmer on. That said, I see no reason why a tank couldn't evolve similar resistance to quinine and leave chloroquine untouched instead.....as they say, "Life finds a way.")

(If you are interested, pursue studies in humans of evolved malaria strains resistant to quinine related products). In the case of velvet (oodinium) in our marine aquaria I feel that CP is the best treatment method as it may operate on more than one stage of the life cycle. In addition, the oodinium life cycle is highly deterministic. As such the 14 day treatment protocol seems highly effective even if it operates only on the infective stage of the life cycle. The marine biology literature for using CP for treatment of cryptocaryon irritans is comparatively sparse and with the back end of the life cycle being non-deterministic, the degradation you are experiencing becomes potentially more relevant.

 

[ThRoewer]

... with the back end of the life cycle being non-deterministic, ...

This is only relevant for treatment in an infected DT.
If you treat in a clean HT and do at least one transfer (or rigorous tank disinfection) after a week, two weeks CP should be also enough for Cryptocaryon.

 

[alprazo]

This is only relevant for treatment in an infected DT.
If you treat in a clean HT and do at least one transfer (or rigorous tank disinfection) after a week, two weeks CP should be also enough for Cryptocaryon.

Totally agree in theory. As for the 72 days. Probably similar to a 45+ yo women becoming pregnant naturally. It almost never happens and when it does the odds of genetic abnormalities are very high.

 

[snorvich]

This is only relevant for treatment in an infected DT.
If you treat in a clean HT and do at least one transfer (or rigorous tank disinfection) after a week, two weeks CP should be also enough for Cryptocaryon.

Of course if you are doing sufficient transfers, CP is irrelevant.

 

[ThRoewer]

Only if Cryptocaryon is your only concern. IMO there are much scarier things out there and two (three) of them (Amyloodinium, Brooklynella, Uronema) can be reliably extinguished by CP, so I rather not forgo it.

 

[snorvich]

Only if Cryptocaryon is your only concern. IMO there are much scarier things out there and two (three) of them (Amyloodinium, Brooklynella, Uronema) can be reliably extinguished by CP, so I rather not forgo it.

Well, at least amyloodinium and Brooklynella.

 

[alprazo]

Is there proven success with Brook? I have personally not run into it since using CP and I have not seen any definite successes here on the board. Anyone?

 

[snorvich]

Is there proven success with Brook? I have personally not run into it since using CP and I have not seen any definite successes here on the board. Anyone?

I think there was anecdotal success somewhere in the first CP thread. I only use CP for velvet.

 

[ThRoewer]

Brook is still best dealt with in formalin baths.

This article cites some experiments that show CP is able to kill Uronema: Chloroquine: A "New" Drug for Treating Fish Diseases
It also states it's effectiveness against Cryptocaryon and Amyloodinium.

I would risk a guess that if CP is effective against those 3 it may also have effect on Brooklynella. It would for sure be nice if someone would do some testing on it.

The most interesting part to me was the test method they used for testing CP concentrations: a UV photometer. Still pricey but magnitudes lower than a HPLC system.

 

[Joules]

I was hopeful that I could get by with UV. Unfortunately, the major degradation products of cp have the same chromophore such that cp can appear to remain at high concentration, even when gone..... you'll figure out if there's an error pretty fast. The white spots would usually disappear within a day after adding cp, but returned when the concentration fell below 5-7 ppm by hplc. If UV says you're at high cp and you still have disease, it's probably time to change tactics.

I plan to see if any of the commonly sold fish antibiotics will kill whatever is destroying cp in my system after I free up one of hospital or QT tanks (where my coral, LR and inverts are living out their 72 day fallow ).

 

[snorvich]

I was hopeful that I could get by with UV. Unfortunately, the major degradation products of cp have the same chromophore such that cp can appear to remain at high concentration, even when gone..... you'll figure out if there's an error pretty fast. The white spots would usually disappear within a day after adding cp, but returned when the concentration fell below 5-7 ppm by hplc. If UV says you're at high cp and you still have disease, it's probably time to change tactics.

I plan to see if any of the commonly sold fish antibiotics will kill whatever is destroying cp in my system after I free up one of hospital or QT tanks (where my coral, LR and inverts are living out their 72 day fallow ).

Are you sure the CP degradation is biological? Have you tested in a barren tank with freshly made saltwater?

Also, the white spots for cryptocaryon are beneath the skin and as far as I know, CP only acts on the theront stage of the life cycle.

 

[ThRoewer]

...

Also, the white spots for cryptocaryon are beneath the skin and as far as I know, CP only acts on the theront stage of the life cycle.

The CP will get into the fish's bloodstream and other bodily fluids as they constantly ingest water for osmoregulation.
So even if the theronts are below the skin and not exposed to the surrounding water they will be exposed to CP by feeding of the CP laced fish.

 

[nuxx]

Would increasing the temperature have any effect on speeding up the life cycle?

The more stocked my tank gets the more I wonder if anything were to ever slip by, if I'd go the fallow route.

Has anyone with any credit, ever tried to treat ich with ParaGuard everyday for a full cycle?

Just asking, because I know for the most part it can be used in a reef tank.

I use paraguard as a gentle "catch all" treatment on new fish before Cupramine, and I know Seachem says it treats ich. I know it's not as effective as TTM, Copper or Hypo if effective at all. Just want to know if it's been proven NOT to work by an advanced hobbyist.