Is hypo a real cure? Possible Loopholes?

[NexDog]

Hi Steven,

I read your article a long time ago and based alot of my QT proceedures on it but now I've had a chance to witness many different QT cycles I'm starting to question the wisdom of hyposalimity.

Basically,I think 6 weeks is too long for hypo. I think the affect on a fish's kidneys is very much underplayed and that 6 weeks is enough to give many fish kidney failure (tangs for sure). I used to do 6 weeks but my last cycle was such a disaster that I've rethought the whole process. I now have a UV Steriliser on my 50g QT and doing 4 weeks hypo. My theory is that if the tomont stage of crypto isn't killed within 4 weeks then it's not going to happen. Also from what I've seen it takes 14 days for hypo to kill invert lifeforms and Ich stays in the tomont stage from anywhere from a few days to a months. If the tomonts release the tomites (or free-swimming theronts) within 2 weeks then I'm starting to question whether hypo can be effective. The parasitic stage (or trophant stage) is said to be the most resistant and usually lasts a week before they drop off into tomonts once more.

So if the tomont stage doesn't last long enough, is hypo effective? Or will hypo also kill the trophant stage parasite? Even so, the trophant phase is too short. This parasite is going through a constant metamrophosis and if hyposalinity can't kill all stages then it's a bit of a gamble? Hypo causes the cell membranes to breakdown and if this molecular destruction is not carried over to the next stage of the parasite's life cycle and the counter is continually "reset" then I doubt hypo can be effective in 100% of cases.

Thoughts?

[jeffbrig]

Steven,

Let me add some of my experiences to Laurence's observation.

We had an achilles tang in QT who experienced swelling in his midsection right around the 6 week mark of hyposalinity. It affected the operation of him swim bladder, and he was listing severely, but was still able to swim and eat somewhat. After a few days without improvement, we continued to raise the salinity, and the fish recovered. Six month later, he's still the model of health in our main tank.

Currently we have another group of fish in the QT, right at the 6 week mark. A purple tang who has been very healthy and a voracious eater up to now has experienced a sudden decline in health. HLLE (somewhat expected in QT confines), pinched lower abdomen, skin discoloration, some white spotting (not ich), and almost no interest in food. He may also be showing some swelling in the midsection, but it's hard to be sure since he's pinched below that.

We're starting to wonder, much like Laurence, if the stress of a 6 week hypo is beginning to trigger other problems. I'm not quite ready to doubt the treatment's effectiveness against ich (after all, we've seen no signs after hypo), but I am developing some concern about the overall effects.

[Steven Pro]

Here is a little excerpt from an email from Dr. Angelo Colorni:

"The success in the hyposalinity treatment lies in the rapidity in which it is carried out. The osmotic shock damages the tomonts at the bottom of the tank (the bacteria then complete the job), whereas it has very little effect, if any at all, on the trophonts in the fish epithelia."

A lot of people are freaked out by dropping the salinity rapidly and you will see most message board participants recommending a gradual shift. I have always just dropped fish right into hypo without any adjustment period out of convenience. But, it turns out that is the best way to deal with the parasite.

As to its long-term effects, I have not seen problems with a one month treatment, but it could certainly be possible. I am aware of at least one study with Emperor angelfish kept for months in hyposalinity with no apparent ill effects, but I have not read the paper yet, so I can't really comment too much.

[NexDog]

Hmmm, still leaves too many unanswered questions and it seems strange that we are only hearing this now. What if there are no tomonts when the tank is dropped to hypo? What if the parasite is in the trophant stage?

By the way I agree that Angels are pretty tough when it comes to hypo. My juvie Emp was the only fish to come out unscathed on the last round.

Also, hypo seems to kill any invert life forms including pods but it takes 2 weeks from what I've seen (by applying hypo to live rock) and I find it hard to believe it woldn't kill the trophant as well but the issue is that the parasite isn't in this stage for long enough.

Doesn't Dr. Colorni's response seem odd to you? If that was the case we could lower to hypo within 48 hours, wait a week for the bacteria to "complete the job" and then raise teh salinity and we done. What's the 4-6 weeks for?

[NexDog]

Steven, any updates?

[Steven Pro]

Dr. Colonri's original work with hyposalinity came up with the recommendation to drop the salinity to 10 g/l (which I believe is equivalent to 10 ppt) for 3 hours every three days for four treatments (Colorni, 1987). This was both a quick lowering and subsequent raising of the salinity. Over time, the hobby made changes to his treatment. We simply lower and keep it low because it was easier than monkeying around with the salinity. Then we started slowly lowering and raising the salinity because we were scared we would shock the fish.

That is not to say that prolonged hyposalinity is not an accepted method of treatment. It is (Noga, 2000). But, I can see no reason to not lower the salinity quickly and abruptly. I drop fish right into hypo without any acclimation for anything other than temperature. But, I do raise them slowly back to full strength seawater when the treatment is complete. I think the slow lowering that is common amongst hobbyists is the problem.

Colorni, Angelo. 1987. "Biology of Cryptocaryon irritans and strategies for its control" Aquaculture 67:236-237.

Noga, Edward J. 2000. Fish Disease: Diagnosis and Treatment. Ames, IA: Iowa State University Press. pages 97-99.

[NexDog]

Thanks for the response. I'm interested to read more about how hypo kills the parasite. Do you have links to any online resources from Dr. Colorni or Edward Noga?

[Steven Pro]

Sorry, but both of those are print references. You might want to check with a local university library, particularly one with a marine biology department.

[fish head steve]

Treatment Option 5 - Daily Water Changes:

"....is my preferred first course of action. Fish are put into a quarantine/hospital tank and then everyday for two weeks the tank is completely cleaned and a 50% water change is performed. ........This method helps to remove the tomites, tomonts, and theronts from the tank and lessens the chance of reinfection. The fish should remain in quarantine for an additional month to ensure the treatment has worked...."

by cleaning the tank, I assume you mean a scrub (with a scotchbrite pad etc.) with the fish in the tank. That would seem to cause a lot of stress to be rearranging the tank on a daily basis for the cleaning.

Is this still your preferred course of action or hypo?

[Steven Pro]

The procedure excerpt above is to be conducted in a QT tank, so rearranging decorations is not that difficult. But yes, I would scrub the tank with an aquarium safe pad.

As to my preferred treatment, I have been using copper more often than other treatments just for convenience sake.

[fish head steve]

One additional question: Has there been any explanation in regards as to why only one fish in a display may show signs of infestation when that tank is clearly infected?

Thanks ~

[Steven Pro]

<a href=showthread.php?s=&postid=7208496#post7208496 target=_blank>Originally posted</a> by fish head steve
One additional question: Has there been any explanation in regards as to why only one fish in a display may show signs of infestation when that tank is clearly infected?

Thanks ~ Previous non-lethal exposure to the parasite can illicit a natural, acquired immunity that protects those individual fishes.

[fish head steve]

Has anyone in the trade or research community done any experiments with UV or Ozone?

[Steven Pro]

I discuss UV and ozone in part two of my series on treatment options for marine Ich.

[Mark]

Question for those who experienced fish declining in health long-term in hypo.... Do you guys watch your pH and Alkalinity? I notice these are hard to keep at adequate levels with low salinity. I usually rememdy it with large water changes every few days, and lots of crushed coral. The reason I ask, is because I have treated tangs, angelfish, and gobies for 6 weeks without ill effects. When I see coloration begin to fade, it usually coincides with alk and/or pH issues for me.

[NexDog]

Alk for me is no problem as our alk is naturally high. I do water changes about every 3 days and add PH buffer at the same time to maintain that. Low PH will certainly kill a fish after 3 weeks or so.

[Sun_Shining]

A lot of people are freaked out by dropping the salinity rapidly and you will see most message board participants recommending a gradual shift. I have always just dropped fish right into hypo without any adjustment period out of convenience. But, it turns out that is the best way to deal with the parasite.

I read you article. When you say shock with hyposalinity.. I assume you mean taking the fish out of reg salininty and dumping them into hyposalinity. Thats great if you are moving the fish.

However, if you need (for any number of reasons) to keep the single fish in the original tank, how can you drop the salinity that fast? I am currently using hyposalinity to treat a Ick infested Volitan Lion who lives in his tank alone. We dropped the salinity by half the first day, then again the second day, by changing out half the water each time and replacing with fresh, then waiting to make sure the salinity reading was constant. Its still only at 1.015 which is still, based on your article, too high. So I'll have to change it again later today/tomorrow.

Would that still qualify as dropping the salnity dramatically? Or is it really too slow to be effective?

[Steven Pro]

I am unsure if this will make the treatment ineffective. It may very well increase the amount of time you have to treat, though. A lot of people are maintaining fish in hyposalinity for one month after all spots disappear.

[Sun_Shining]

It may very well increase the amount of time you have to treat, though.

Since he is the only one in the tank, that is not that big of a deal. Thank you for your reply. =)