Black mollies

[TCFletch]

My DT has or had ich/velvet. I removed the fish and corals. I left the rock and sand in DT. It's been running fallow for 40 days or so. I also put a black Mollie in the sump about 10 days ago and the fish is doing great! He thinks he owns the place. Anyway the fish isn't showing any signs of ich/velvet. So my question is: is it safe to put my tangs back in my DT? Is my tank now ich-free? Molly is good so my tangs should be good. Right?

 

[Humblefish]

There is a flaw to the black molly test now that I stop and think about it. Let's say your DT was infested with the "72 day variant" of ich encountered during the Colorni and Burgess study. The study states:

Even under identical incubation conditions tomonts vary considerably in the time required to form theronts (Nigrelli and Ruggieri, 1966; Colorni, 1992; Burgess and Matthews, 1994a; Diggles and Lester, 1996b). Thus, theront excystment is very asynchronous, occurring between 3 and 72 days and peaking at 6 ± 2 days (Colorni, 1992). This differs significantly from I. multifiliis, where the theront excystment takes only 18-24 h at 23C (Dickerson and Dawe, 1995).

The reason for asynchronous excystment is unclear. There is no relationship between the tomont size and excystment time (Nigrelli and Ruggieri, 1966; Colorni, 1992; Diggles and Lester, 1996a,b). In fact, a large and a small tomont may produce theronts at the same time, even though the smaller tomont undergoes fewer divisions. When tomites do not form until at least 2 weeks, a mass of endoplasm remains undifferentiated and fewer live theronts are produced (Colorni, 1992). Whatever the cause, asynchronous excystment prevents simultaneous exhaustion of all tomonts, facilitates theront dispersal in time and appears so advantageous to C. irritans that the phenomenon should be interpreted as a strategy for survival (Colorni, 1985).

Does theront excystment taper off significantly and become erratic after 6 days? If you put the black mollies in on Day 30 (for example), but more theronts weren't released by the tomonts until Day 45 (for example); then 7 days wouldn't be enough exposure time for symptoms to show. (Remember, free swimming theronts have to be present in the water to latch onto the fish, become trophonts and white dots to show up.)

For this reason, it would be best not to do the black molly test until after the 76 day fallow period IMO.

 

[TCFletch]

I must be turning into a parasite geek because this is all starting to make sense! And that's scary. Lol. Thanks for the lesson and happy reefing. By the way; fish are going back into DT next weekend; ich or no ich! We'll find out.

 

[bevo5]

Hey all - I just want to revisit this slightly old thread.

I find this black molly test thing fascinating as I never would have thought about it, but it totally makes sense.

If I'm reading Humble's post correctly, then we should wait until the 76 days and THEN do the Ich test because some of the little buggers could lay dormant and/or just take a while cycle through. Is that the gist of it?

So we drop the black mollies in and give 'em a week or so.

Additional question - i have a 200g tank. If I put three black mollies in what are the realistic chances that a spore would even find one of them?

 

[melypr1985]

If I'm reading Humble's post correctly, then we should wait until the 76 days and THEN do the Ich test because some of the little buggers could lay dormant and/or just take a while cycle through. Is that the gist of it?

Yup. that's it.

So we drop the black mollies in and give 'em a week or so.

Yup again.

Additional question - i have a 200g tank. If I put three black mollies in what are the realistic chances that a spore would even find one of them?

I'm not good at odds, can't help there.

 

[Humblefish]

@bevo5 Yes, it would be best to wait 76 days before doing the black molly test. Because if you were to do it too soon and get a hit (i.e. visible trophont on a molly), then the fallow period would have to start all over again after you removed the black mollies.

I don't know the odds either, but if your mollies go a week and are still clean then you are probably good to go.

 

[bevo5]

Thanks all - good stuff.

I just started a fallow period, and I'm very excited about the start over...being able to do things 100% correctly.

 

[ltrace]

I am at the end of 76day, actually 80day fallow period. I want to do the black molly test. What is the process to acclimate them to salt water? How long before putting them into the DT?

 

[Areseebee]

I've never heard of this, what is the point of using a black Molly as your canary rather than just any fish you already own? Do they show ich more reliably? I get that being all black is helpful to seeing them.

 

[ltrace]

With them being a fresh water fish and never having been in saltwater. They would very easily contract ich or any other disease that maybe lingering in the DT after a fallow period. Why would you risk a fish that has gone through the whole QT process to rid it of any disease that it may have had? Then put it back in the DT to discover that something was still lingering in the DT.

 

[4FordFamily]

@bevo5 Yes, it would be best to wait 76 days before doing the black molly test. Because if you were to do it too soon and get a hit (i.e. visible trophont on a molly), then the fallow period would have to start all over again after you removed the black mollies.

I don't know the odds either, but if your mollies go a week and are still clean then you are probably good to go.

X2 I would say the parasites are great at finding a host, especially one with an amine system that cannot fight back

 

[GHsaltie]

^That and mollies are a whole heck of a lot easier to catch than any saltwater fish, even clowns .

 

[4FordFamily]

^That and mollies are a whole heck of a lot easier to catch than any saltwater fish, even clowns .

This is true!

And when you use black ones, any ailment is easily visible!

 

[Areseebee]

With them being a fresh water fish and never having been in saltwater. They would very easily contract ich or any other disease that maybe lingering in the DT after a fallow period.

Just curious, is this assertion evidence based? Have there been studies on this?

Why would you risk a fish that has gone through the whole QT process to rid it of any disease that it may have had? Then put it back in the DT to discover that something was still lingering in the DT.

Either way you've now reset your DT clock and either way you now own a fish with Ich that you have to treat.

 

[melypr1985]

Just curious, is this assertion evidence based? Have there been studies on this?


Either way you've now reset your DT clock and either way you now own a fish with Ich that you have to treat.

It's been tested more than a few times. It's simple really. A fish that has never been exposed to a disease or parasite will have no immunity for it and therefore easily and quickly contract said parasite or disease. Being black, the parasites will be easily visible.

Yes, if you have failed in your fallow period or QT measures, then you will have to reset your clock, but having to catch one slow molly is much better than having to catch all your fish back out of the DT and QT them all again. The molly can simply be returned to freshwater and the parasites will not survive.

 

[Areseebee]

It's been tested more than a few times. It's simple really. A fish that has never been exposed to a disease or parasite will have no immunity for it and therefore easily and quickly contract said parasite or disease.

Ok, when I read the immunology arguments I always feel like we are playing REALLY fast and loose with how the immune system works and these common sense arguments often end up being misleading. I'm totally comfortable with it as an evidence based assertion.

The molly can simply be returned to freshwater and the parasites will not survive.

This is a big difference! If the treatment is easier then it totally makes sense (I wasn't sure how quickly Molly's can go back and forth).

 

[Humblefish]

Most public aquariums use the "black molly test" to see if a DT is truly disease-free before restocking it. The downside is free swimming parasites/free floating bacteria must be active in the water for it to work. If tomonts are still encysted, but haven't released any free swimmers in a while, nothing will show up. Thus it's a good idea to leave the black mollies in your system for at least a week or two just to be sure. Also, black mollies don't handle high flow very well, so turn your pumps way down, or put the mollies in a "Kritter Keeper" or in your sump or something.

This article has more info on keeping mollies in SW (including how long to acclimate): http://hubpages.com/animals/Keeping-Breeding-and-Raising-Saltwater-Mollies

 

[Connor SKKY02]

It's been tested more than a few times. It's simple really. A fish that has never been exposed to a disease or parasite will have no immunity for it and therefore easily and quickly contract said parasite or disease. Being black, the parasites will be easily visible.

Yes, if you have failed in your fallow period or QT measures, then you will have to reset your clock, but having to catch one slow molly is much better than having to catch all your fish back out of the DT and QT them all again. The molly can simply be returned to freshwater and the parasites will not survive.

Just wondering if the molly get saltwater ich or velvet... and I put him back into freshwater. How long the molly has to be in freshwater to make sure the parasites are dead?

 

[Hermie]

For the record, mollies should not just be "dropped" into the tank, they should be acclimated to brackish water (approx 1.010 SG) for at least 24 hours before going into full marine salinity.