Black Mollies in QT

[Marco S]

I am getting a Naso Tang and a pair of Blue Jaw/Blue Throat Triggers in next week and have already started setting up the QT. I have watched a lot of YouTube videos, (mostly with @Humblefish ) where they use Black Mollies to test for any diseases after a successful QT and I was planning on picking some up and getting them converted to saltwater next week as well. I was just wondering if I need to Qt the Mollies before adding them to the clean observation tank or not. I do plan on adding the Mollies to my display as well. I am pretty sure that the saltwater will kill any freshwater diseases, but not 100% sure so I figured I would ask. I have QT'd EVERYTHING wet that has gone into my display so far and do not want to take any chances at this point.

I am not looking for guesses btw...if you do not know 100% then please do not comment.

 

[hds4216]

No freshwater diseases are euryhaline enough to survive both fresh and marine conditions. If you use freshwater mollies, there is no risk of disease introduction through them.

I should note that you should have a plan for these mollies once you buy them and after you're done with them. I'm not sure they'll coexist well with a trigger.

 

[Marco S]

No freshwater diseases are euryhaline enough to survive both fresh and marine conditions. If you use freshwater mollies, there is no risk of disease introduction through them.

I should note that you should have a plan for these mollies once you buy them and after you're done with them. I'm not sure they'll coexist well with a trigger.

Thank you for the reply!

And they will be going in a smaller DT with some Dartfish, Clownfish and a Dottyback a Blenny and some cleaner shrimp and snails, not my larger DT with the Tangs and Triggers.

 

[EakTheFreak]

No freshwater diseases are euryhaline enough to survive both fresh and marine conditions. If you use freshwater mollies, there is no risk of disease introduction through them.

I should note that you should have a plan for these mollies once you buy them and after you're done with them. I'm not sure they'll coexist well with a trigger.

+1
I’ve used the freshwater black Molly routine in QT for my Copperband Butterfly and (3) Blue Star Leopard Wrasses.

The only ultra rare thing you would have to confirm is that the black mollies were never saltwater fish before. The key is actually buying them from big box store.

If someone would have used black mollies converted them to salt for QT then back to fish store they would have a built up immunity to saltwater disease which eliminates the entire purpose of black Molly’s in QT.

Again, super rare of that happening especially if you go big box store for your Molly’s.

good luck!

 

[Jay Hemdal]

I am getting a Naso Tang and a pair of Blue Jaw/Blue Throat Triggers in next week and have already started setting up the QT. I have watched a lot of YouTube videos, (mostly with @Humblefish ) where they use Black Mollies to test for any diseases after a successful QT and I was planning on picking some up and getting them converted to saltwater next week as well. I was just wondering if I need to Qt the Mollies before adding them to the clean observation tank or not. I do plan on adding the Mollies to my display as well. I am pretty sure that the saltwater will kill any freshwater diseases, but not 100% sure so I figured I would ask. I have QT'd EVERYTHING wet that has gone into my display so far and do not want to take any chances at this point.

I am not looking for guesses btw...if you do not know 100% then please do not comment.

Here is an excerpt from my upcoming disease book on this topic. The third paragraph discusses the main issues:


Using black mollies to screen an aquarium for Cryptocaryon

In recent years, a procedure has been promoted that uses marine-adapted freshwater mollies to screen for active Cryptocaryon infections in marine aquariums. The thought is that black mollies that are naïve to marine ectoparasites, will soon develop infections if the disease is present in the aquarium. Being black, these parasites will show up in contrast, making their identification much easier. Mollies have also been suggested to be housed alongside sensitive fish (that cannot be easily medicated) to serve as a “canary in the coal mine” for active disease.

The basic process is to acquire a small group of freshwater black mollies and gradually acclimate them to seawater over a period of 5 to 7 days. They then are added to the previously fallow aquarium, or added to the quarantine tank, and then observed for at least two weeks to see if they develop ectoparasites. If they do, then a treatment needs to be instituted, or the fallow period extended.

As with many aquarium ideas, over-extrapolation can reduce the effectiveness of the original idea. The process is really only suited to screen for Cryptocaryon. Brooklynella may not even infect mollies. Uronema and Amyloodinium can survive salinities as low as 3 ppt so may already be present in “freshwater” mollies that have been raised in brackish fish ponds. Marine and freshwater fish have basically the same internal salinity. Therefore, untreatable internal diseases, such as viruses and Myxozoans could possibly be brought into an aquarium with the mollies.

There is a huge risk for introducing euryhaline trematodes into an aquarium along with black mollies. Fish farmers, wholesalers and retail dealers all understand that mollies benefit from being housed in brackish water, and so they usually add salt to systems housing mollies in order to reduce mortality under crowded conditions. Euryhaline trematodes take advantage of this, the trouble is that some of these can survive marine conditions and then hyposalinity is ineffective as a treatment for them.

Finally, here have been no actual studies that indicate this method is actually effective, it is based on sound theory, but needs to be better tested. This process does seem to have benefit in screening for Cryptocaryon, but falls short for other diseases.

 

[Marco S]

Here is an excerpt from my upcoming disease book on this topic. The third paragraph discusses the main issues:


Using black mollies to screen an aquarium for Cryptocaryon

In recent years, a procedure has been promoted that uses marine-adapted freshwater mollies to screen for active Cryptocaryon infections in marine aquariums. The thought is that black mollies that are naïve to marine ectoparasites, will soon develop infections if the disease is present in the aquarium. Being black, these parasites will show up in contrast, making their identification much easier. Mollies have also been suggested to be housed alongside sensitive fish (that cannot be easily medicated) to serve as a “canary in the coal mine” for active disease.

The basic process is to acquire a small group of freshwater black mollies and gradually acclimate them to seawater over a period of 5 to 7 days. They then are added to the previously fallow aquarium, or added to the quarantine tank, and then observed for at least two weeks to see if they develop ectoparasites. If they do, then a treatment needs to be instituted, or the fallow period extended.

As with many aquarium ideas, over-extrapolation can reduce the effectiveness of the original idea. The process is really only suited to screen for Cryptocaryon. Brooklynella may not even infect mollies. Uronema and Amyloodinium can survive salinities as low as 3 ppt so may already be present in “freshwater” mollies that have been raised in brackish fish ponds. Marine and freshwater fish have basically the same internal salinity. Therefore, untreatable internal diseases, such as viruses and Myxozoans could possibly be brought into an aquarium with the mollies.

There is a huge risk for introducing euryhaline trematodes into an aquarium along with black mollies. Fish farmers, wholesalers and retail dealers all understand that mollies benefit from being housed in brackish water, and so they usually add salt to systems housing mollies in order to reduce mortality under crowded conditions. Euryhaline trematodes take advantage of this, the trouble is that some of these can survive marine conditions and then hyposalinity is ineffective as a treatment for them.

Finally, here have been no actual studies that indicate this method is actually effective, it is based on sound theory, but needs to be better tested. This process does seem to have benefit in screening for Cryptocaryon, but falls short for other diseases.

Thank you for the information. I think I will just stick to my original QT method of Copper Power at therapeutic levels for 14 days, then transfer to another tank for 2 doses API General Cure and then observation for a couple weeks. This has been great in keeping diseases out of my DT for the last few years.

I just wanted a sure fire way to verify a successful QT since I have not added anything to my DT in a long time and I do not want to take any chances of bringing anything into the DT after all the time, effort and money I have spent so far. But it sounds like I will be adding more risk than benefit with the Mollies, so I think I will wait until more research has been done before trying it for myself.

Thanks again!