How long to quarantine after Uronema marinum

[Brieninsac]

In December, I started a thread about three Green Chromis that were showing signs of Uronema marine.

http://www.reefcentral.com/forums/showthread.php?t=2545669&highlight=proper+diagnosis

Since then two have died, only the largest, strongest Chromis from the original batch is all that remains.

I finished treating the QT with Seachem ParaGuard about 2 weeks ago. I've been doing weekly water changes of about 40%.

Even though the last Chromis never showed any signs of Uronema marine I have to assume he had the parasite too. With that said I need to know how long I should keep him in quarantine.

We're planning a trip to Maui in mid March. It will be over 60-days at the first of March. I'm concerned about moving him to my DT a mere 2-weeks before our trip where I won't be able to monitor him and the other inhabitants while we're gone. I would be devastated if fish in my DT get sick while I'm gone and can't do anything about it.

I know Ich has a 84-day life cycle and wondered if the same applied to Uronema marine.

 

[Deinonych]

Uronema is a free-living parasite that can survive without a fish host. Were I in your situation, I would perform a formalin dip on the fish and transfer it to a clean, sterilized aquarium for observation. The dip should kill any parasites on the fish, and the clean aquarium will ensure additional parasites do not reinfect the fish.

If the fish doesn't show signs after a few weeks of observation, you're probably in the clear.

 

[Jade5051]

I had Uronema show up on an Anthias about 27 days into the QT process. I'd say you want to keep them QTed for 4-6 weeks.

 

[ThRoewer]

Uronema doesn't have a on-fish off-fish lifecycle like ich or velvet, it reproduces directly without a cyst stage.

Uronema is also not really a parasite but rather an opportunistic organism that invades fish with wounds (can be the tiniest scratches) and/or compromised immune systems.
Normally it feeds on bacteria and detritus and has no interest in healthy fish. But when a fish has the tiniest injury with a secondary infection uronema may follow to feed on those bacteria. That in itself wouldn't be a problem, but unfortunately uronema excretes a poison that kills more tissue and therefore produces more feeding grounds. Once uronema gets into the fish's blood stream the fish is doomed.

In essence, uronema can be present at all times without doing any harm. But when a fish with a compromised immune system has an injury it may infect it.

Formalin is a good measure to kill uronema.

My suggestion in your case would be to dose the QT you hold your survivor in with the short bath concentration of formalin (1ml per US gallon). 45 to 50 minutes after dosing the tank transfer him to a sterilized QT to hold him in for the duration of your trip.

When he is still fine after you return I would repeat the formalin treatment and then put him into the Display or wherever else you want to home him.

I would definitely not add him to the display shortly before a longer absence - too many things could go wrong.
If you can't leave him in a QT I would rather return him to a LFS - one chromis is not worth the risk.

 

[snorvich]

What ThRoewer said. I do not advocate chromis at all due to the prevalence of uronema with that species (at least for the last five years or so)

 

[ThRoewer]

The issue with (green) chromis and many Anthias is that they have an extremely high metabolism and therefore high oxygen demand. On top of that, due to their small size, they are usually "gang-packed" for shipping (at least from collection site to exporter) and at holding facilities.
While they seem to form large formations in the wild and get along well with each other they in fact constantly fight, especially when cramped together to hundreds in tanks that often don't even offer the space one individual claims for itself in the wild.
So they are stressed to the max, covered with little wounds from countless scuffles and are weakened by suboptimal holding conditions.
It is no wonder that they get sick and infect each other.