Microscopy versus Quarantine

[jpcaram]

I was wondering about the possibility of looking for parasites under the microscope as an alternative (or in addition) to quarantine in general. This came to mind in the context of me needing to add a large crew of Emerald crabs to help combat a bubble algae outbreak ASAP. But my interest at this point is more general and would like to start such discussion.

Quarantine is a "blind" approach. We do it because we don't know what our creatures may be carrying. So, we quarantine for the largest term that would cover the lifespan of the longest living possible parasite. But what if we use methods to no be so blind? Like taking a sample and inspecting it under the microscope?

Of course there are difficulties. How do we take a sample? Swabbing the shell of a crab or snail may be much easier that swabbing the skin of fish. And if we do so, are we getting the sample from the right place? Maybe certain parasites only live in the digestive system and not on the skin. Do we then sample the droppings? Are some parasites too small for hobby-grade microscopes?

There seem to be a lot of questions. Possibly many that I haven't thought of. As well as your opinion, it would be most valuable to hear from those who have attempted such diagnostics, their methods and results.

 

[Stealthreefer]

It takes 90 days of quarantine to say something is successfully quarantined, imo.

Stuff in the cyst stage would be super easy to miss and because the life cycles of these things range from hours to months it would be super easy to miss.

 

[vetteguy53081]

I was wondering about the possibility of looking for parasites under the microscope as an alternative (or in addition) to quarantine in general. This came to mind in the context of me needing to add a large crew of Emerald crabs to help combat a bubble algae outbreak ASAP. But my interest at this point is more general and would like to start such discussion.

Quarantine is a "blind" approach. We do it because we don't know what our creatures may be carrying. So, we quarantine for the largest term that would cover the lifespan of the longest living possible parasite. But what if we use methods to no be so blind? Like taking a sample and inspecting it under the microscope?

Of course there are difficulties. How do we take a sample? Swabbing the shell of a crab or snail may be much easier that swabbing the skin of fish. And if we do so, are we getting the sample from the right place? Maybe certain parasites only live in the digestive system and not on the skin. Do we then sample the droppings? Are some parasites too small for hobby-grade microscopes?

There seem to be a lot of questions. Possibly many that I haven't thought of. As well as your opinion, it would be most valuable to hear from those who have attempted such diagnostics, their methods and results.

Based on life cycle, 30-45 days is safe range to assure no infection but not swabbing but skin scrapes can determine any foreign cysts, bacteria, etc IF properly identified. Quarantine also assures stop of spread to other occupants and is a safer gamble opposed to simply dropping a fish into a tank with the unknowns.
I see where you are getting at with your theories, but what you describe isnt practical although may be effective with many hobbyists.

 

[Dom]

I question the practicality of pulling fish and taking a sample. What if the fish you take a sample from isn't the one infected? Or what if you take a scraping from a fish in an area where there are no parasites?

It seems like a lot of work to me. I do a 90 day QT just to be safe and then introduce them into the display.

 

[Jay Hemdal]

I was wondering about the possibility of looking for parasites under the microscope as an alternative (or in addition) to quarantine in general. This came to mind in the context of me needing to add a large crew of Emerald crabs to help combat a bubble algae outbreak ASAP. But my interest at this point is more general and would like to start such discussion.

Quarantine is a "blind" approach. We do it because we don't know what our creatures may be carrying. So, we quarantine for the largest term that would cover the lifespan of the longest living possible parasite. But what if we use methods to no be so blind? Like taking a sample and inspecting it under the microscope?

Of course there are difficulties. How do we take a sample? Swabbing the shell of a crab or snail may be much easier that swabbing the skin of fish. And if we do so, are we getting the sample from the right place? Maybe certain parasites only live in the digestive system and not on the skin. Do we then sample the droppings? Are some parasites too small for hobby-grade microscopes?

There seem to be a lot of questions. Possibly many that I haven't thought of. As well as your opinion, it would be most valuable to hear from those who have attempted such diagnostics, their methods and results.

The trouble is in proper identification of the propagules you might see. I can tell Neobenedenia eggs pretty easily due to their distinct shape. However nobody can really visually ID an ich tomont - they are just too non-descript.

I routinely examine fish FW dips as a diagnostic tool - even then it can be tough, you see little balls of mucus and it is difficult to know if they are disease causing or not.

eDNA testing, like that offered by Aquabiomics may have a benefit for this sort of thing, but it is a new technique when applied to aquariums.

Jay

 

[jpcaram]

We know quarantine works. But can we perhaps do better? Is there something to be learned by examining samples at the beginning, during, or at the end of the quarantine period? If we decide to shorten that period (I'm pretty sure most people don't do the full 90 days), can we gain more confidence by "looking closer"?