How does subtherapeutic copper "Mask" Ich/Velvet symptoms?

[PGT253]

Hello. I've heard that sub-therapeutic level of copper can mask typical symptoms of ich/velvet so I'm wondering what exactly happens in these cases. Is copper exposure slow down parasites feeding duration or put them into sleep/hibernate mode?

 

[Fishfinder]

@Humblefish

 

[melypr1985]

It can kill a portion of the parasites but not all. The result of this is that they population is controlled enough to keep visible signs to a minimum. This means that a fish could show no symptoms but still be harboring the parasite in low numbers in the gills. A week or two after they are removed from this sub therapeutic level of copper the parasite has had time to breed and rise in numbers and now the fish is in trouble and so are the others it is exposed to.

 

[Humblefish]

Subtherapeutic copper eliminates some of the free swimmers, but not all, so the fish continues to be exposed to them at low levels. The fish's immune system begins to develop immunity/resistance to the parasites the longer it is subjected to sublethal concentrations. However, once copper is removed from the equation the parasites multiply exponentially and that usually overwhelms the fish. But it can sometimes take awhile (or on rare occasions not happen at all) based on just how strong the developed resistance is to the pathogen originally being suppressed.

Back in the day (before reef tanks) many would keep ich/velvet in check simply by running low level copper in their DT. Because of this, diseases weren't the big problem they are today. However, back then fish rarely lived to a ripe old age, and I suspect prolonged copper exposure was at least partly to blame.

It's also important to note that low level copper does not always have a successful outcome when managing ich/velvet - not back then and not today.

 

[4FordFamily]

It can kill a portion of the parasites but not all. The result of this is that they population is controlled enough to keep visible signs to a minimum. This means that a fish could show no symptoms but still be harboring the parasite in low numbers in the gills. A week or two after they are removed from this sub therapeutic level of copper the parasite has had time to breed and rise in numbers and now the fish is in trouble and so are the others it is exposed to.

Subtherapeutic copper eliminates some of the free swimmers, but not all, so the fish continues to be exposed to them at low levels. The fish's immune system begins to develop immunity/resistance to the parasites the longer it is subjected to sublethal concentrations. However, once copper is removed from the equation the parasites multiply exponentially and that usually overwhelms the fish. But it can sometimes take awhile (or on rare occasions not happen at all) based on just how strong the developed resistance is to the pathogen originally being suppressed.

Back in the day (before reef tanks) many would keep ich/velvet in check simply by running low level copper in their DT. Because of this, diseases weren't the big problem they are today. However, back then fish rarely lived to a ripe old age, and I suspect prolonged copper exposure was at least partly to blame.

It's also important to note that low level copper does not always have a successful outcome when managing ich/velvet - not back then and not today.

What they said!

 

[PGT253]

Thank you. So technically, sub-therapeutic level of copper will not affect ich/velvet trophont feeding duration (7 days max?)? If I buy a fish kept in low copper level at LFS, will that affect the outcomes of TTM, provided the process is done absolute correctly?

 

[Humblefish]

So technically, sub-therapeutic level of copper will not affect ich/velvet trophont feeding duration (7 days max?)? If I buy a fish kept in low copper level at LFS, will that affect the outcomes of TTM, provided the process is done absolute correctly?

Since copper has no impact on trophonts, it shouldn't prolong (or shorten) feeding time on the fish. The only possibility would be if a theront was damaged (but not killed) by the low copper level, and that caused it to drop off sooner once it morphed into a trophont. But that still wouldn't affect TTM.

TTM will eliminate ich, regardless of whether or not the fish was kept in low level copper beforehand. However, it can take up to 30 days for fish with velvet to show symptoms after being exposed to subtherapeutic copper, and TTM does not treat that disease; only copper or CP will. Remember, we are living in the age of velvet with no end in sight...

 

[PGT253]

I do have a question though, Velvet kills fast because victims are overwhelmed with a sheer number of trophonts due to faster life cycle, then why would it take longer to see Velvet's symptoms? And I don't understand why TTM does not work on Velvet since what TTM/Copper/CP does is keeping the fish re-infected with new parasites. But then Velvet life cycle is already known so one can predict the landing phase and bursting phase of trophonts to avoid re-infection

 

[Humblefish]

I do have a question though, Velvet kills fast because victims are overwhelmed with a sheer number of trophonts due to faster life cycle, then why would it take longer to see Velvet's symptoms? And I don't understand why TTM does not work on Velvet since what TTM/Copper/CP does is keeping the fish re-infected with new parasites. But then Velvet life cycle is already known so one can predict the landing phase and bursting phase of trophonts to avoid re-infection

When a fish with velvet is removed from subtherapeutic copper, the trophonts on the fish are probably few in number. And it is logical to postulate that these surviving trophonts are not in perfect health, since they were exposed to copper poison just recently (as theronts). It likely takes the parasite a few generations (more or less) to make a full recovery and begin reproducing again in full force.

72 hour transfers do not work on velvet because it can complete it's entire lifecycle in as little as 48 hrs, after dropping off the fish. 48 hrs is the minimum, it can take longer dependent upon strain, temperature, exposure to light, etc. 36 hour transfers (wiggle room) might be effective against velvet, but that is still only theoretical and has never been tested.

 

[Humblefish]

^^ Just to add: 72 hour transfers work on ich because 72 hours is the minimal time frame for that parasite to complete it's lifecycle after dropping off a fish. 72 hour transfers have been tested on ich, so it's tried & true: https://www.reef2reef.com/threads/tank-transfer-method.192655/

So it is logical to conclude that 48 hour transfers would work on velvet, because it is based on the same reasoning as 72 hrs for ich. However, I would begin with 36 hour transfers and then work upward (i.e. closer to 48 hrs) with future fish just to be on the safe side. Establish that 36 hour transfers work on velvet first, and then try longer transfers.

 

[Victoria M]

Thank you humblefish for continuing to educate any who are willing to read. Everytime I read your posts my memory is refreshed, or my understanding is expanded. Thank you.

 

[Gmj4409]

++1

 

[Fishfinder]

@Humblefish do you know of anyone who has tried doing a shortened TTM for velvet? (24-36hr) transfers.

 

[Humblefish]

@Humblefish do you know of anyone who has tried doing a shortened TTM for velvet? (24-36hr) transfers.

No one I am aware of. I plan on trying it soon (setting up buku tanks now).

 

[NeuroticAquatics]

I remember hearing of people running subtheraputic levels of copper back in the day, but never did it myself. It’s interesting to see how much has changed.

 

[Brew12]

I do have a question though, Velvet kills fast because victims are overwhelmed with a sheer number of trophonts due to faster life cycle, then why would it take longer to see Velvet's symptoms?

I didn't see where this was answered.

It doesn't necessarily take longer for symptoms to occur as much as it is harder for people to recognize the symptoms. A few large white spots from Ich are fairly easy to see. The spots from Velvet are much smaller and only there for a short period of time for the first generation. It is much less likely that they will be noticed. It isn't until you start getting larger numbers of the parasites during the 2nd and 3rd generations that the visual symptoms become easier to see. By then, the parasite is reproducing full bore.

 

[Victoria M]

I thought HF answered that question very well. Perhaps you missed his thoughts on this. Between your explanation and HF I thought it was good stuff.

When a fish with velvet is removed from subtherapeutic copper, the trophonts on the fish are probably few in number. And it is logical to postulate that these surviving trophonts are not in perfect health, since they were exposed to copper poison just recently (as theronts). It likely takes the parasite a few generations (more or less) to make a full recovery and begin reproducing again in full force.

72 hour transfers do not work on velvet because it can complete it's entire lifecycle in as little as 48 hrs, after dropping off the fish. 48 hrs is the minimum, it can take longer dependent upon strain, temperature, exposure to light, etc. 36 hour transfers (wiggle room) might be effective against velvet, but that is still only theoretical and has never been tested.

 

[PGT253]

@Humblefish do you know of anyone who has tried doing a shortened TTM for velvet? (24-36hr) transfers.

I'm doing it now. Though my pair of clown were exposed to low-level copper before I decided to do TTM. Currently on my 3rd 36 hrs transfer, they look happy

 

[Humblefish]

I'm doing it now. Though my pair of clown were exposed to low-level copper before I decided to do TTM. Currently on my 3rd 36 hrs transfer, they look happy

Keep us updated on your progress.