does QT get rid of parasite?

[viodea]

When a fish stay in QT for a month doesn't show any sign of parasite such as itch, it doesn't mean it has no parasite, does it?

If so, how does QTing a fish guarantee the safety of fishes in DT?

I can see other benefit of QT but not sure about that particular situation?

[melvinudawl]

I don't think a QT by itself will ever fully prevent parasites like ich from getting in your dt. They can lay dormant and unnoticed for quite some time, striking when a fish is otherwise ill or severely stressed. QT is just one more tool for us to lower the risk. Some people do dips, hyposalinity and/or copper treatment to all fish in QT. I think this gives you a much better chance of keeping the tank free of parasites, but nothing is perfect and it's a heck of a lot more stress on your new fish.

[WaterKeeper]

Right on Melvin. Both ich and velvet are obligate parasites meaning the need to find a fish on which to feed at a certain stage of their life cycle. If they don't find a fish they don't form cysts and therefore don't breed. The QT just lets a new fish stay under observation for disease and, if after 4-6 weeks none is seen, the chances are pretty good he is free of those two parasites. The fish is probably healthy as other diseases usually will strike within that time frame as well. It is not a guarantee however.

[1DeR9_3Hy]

Something else to keep in mind, is even though you don't see ich on the fish, it is still there. Ich is on almost all fish all the time (piranha are exempt, for some reason they don't get ich), its just when they get stressed or something lowers the fish's immunity it allows the ich (and/or other parasites/diseases/infections) to become a problem.

But if after 4 weeks, you see nothing on your fish in QT i would say your good to go.

[jenglish]

yeppers, theres no guarantee. I start a QT at 1.016 which is what FO systems are often kept at and is likely what the fish are bieng shipped to you at anyway. 1.009 that is often used as hypo for ich I don't go to unless there is actually signs of ich (knock on wood, there never has been yet) 1.016 discourages parasites but is not a treatment per se. Pre-emptive treatment lowers your risk of having a parasite but is stressing an already stressed fish. I think of true hyposa,inity or copper treatments along the lines of radiation or chemo treatments for people, sometimes life saving but not what I want to put a living creature through for no reason. But thats JMHO :)

[why_drift]

<a href=showthread.php?s=&postid=13970574#post13970574 target=_blank>Originally posted</a> by 1DeR9_3Hy
Something else to keep in mind, is even though you don't see ich on the fish, it is still there. Ich is on almost all fish all the time
If what you are saying is that all fish have ich all the time and that it only shows when they are stressed, I disagree. After looking at as many articles and research i could find i think that it is quite possible to have an ich free tank, where the parasites do not exist at all, in the tank or on the fish.

After all the stress of shipping and being put into QT i would think that if a fish did have ich. it would be a very likely to show signs duing the 5 weeks in QT.

[WaterKeeper]

Thank you Why drift. That ich is always present is pure myth. The ciliate has four distinct life stages and it must complete all to survive. We see the Trophant stage on the fish and that stage lasts a week of less. It then leaves the fish it is a Tomont and in about 18 hours it develops a thick wall and becomes a cyst. This stage is temperature dependant and can last from three weeks to many months at low temperature. Finally the cyst releases a swarm of daughter cells called tomites that must attach to a fish in 18-20 hours or perish. If a host is not found the cycle is stopped and the disease disappears.

I have not seen anything that indicates some other stage that can lay dormant until a stress or other factor restarts this cycle.If someone has an article that supports that theory I'd be glad to read it.

[viodea]

Can tomites attach to a healthy fish?

[WaterKeeper]

Sure can, they really don't ask for the fish to have a physical before they attach to it. The are equal opportunity infectors.

[viodea]

that's what I thought.
So, is QTing a little overrated?

[WaterKeeper]

Not at all, it keeps one from adding sick fish to the display and infecting all the fish in it. It doesn't cure anything but it sure limits the damage.

[tmz]

Somewhere, I've read that less than 30% or so of captured fish have ich. In the wild most don't have it. The confinement in the wholesaler's tanks, retailer's tanks and your tank coupled with the parasites ability to multiply 200 to 300 fold in each life cycle spreads it around very well. While qt and observation for 4 to 6 weeks can give a level of assurance ,it is surely not a certainty that the fish is ich free,. Many fish develop partial immunity after surviving an exposure. While ich is unseen it will often still host in the more vulnerable tissues of the mouth,nostrils and gills of these fish unseen but may breakout and infect other fish or the partaly immune fish at some point. .

If you choose prophylactic treatment for a fish in qt, half measures such as mid point hypo salinity or a few drops of copper will likely do more harm than good,in my opinion, either slowing down the parasite so you can't observe it until normal salinity is returned or helping it to build a resistance to copper or any other medication that is not used at at a therapeutic level for a full course of treatment..

[uscharalph]

Cleaner shrimp can help clean fish of parasites.

[tmz]

<a href=showthread.php?s=&postid=13974813#post13974813 target=_blank>Originally posted</a> by uscharalph
Cleaner shrimp can help clean fish of parasites. :) Maybe some parasites, but studies have been done which show that they don't eat the cryptocaryon irritans parasite(ich). I doubt they would eat velvet(amyloodinium) which is a dinoflagelate algae. Ich parasites embed in the flesh of the fish. The Lystamta amboinesnsis(cleaner shrimp/skunk cleaner shrimp) do pick at the flesh around the wounds left by the ich, leading many to believe they are preying on the ich.There is no reliable effective predator for ich, nor, unfortunately , is there any reef safe way to eradicate them in my opinion/experience. The only proven methods involve taking the fish out of the display and leaving the display fishless for at least 6 weeks The fish are treated in (a) separate tank(s) with copper medication, hyposalinity or the tank transfer method.