Crypto Life Cycle and Treatment Scenario

[Gone Reefin’]

Posting a theoretical question for the fish docs. For the purposes of this scenario, please assume the following:

• Crypto is the only parasite I am addressing
• The QT is 1.009 hypo, although copper could also be subbed in this scenario
• The tank has NO preexisting infection - assume the tank is clean when the QT is started
• This is a QT scenario, not a treatment scenario

Scenario: Fish with no signs of ich infection is introduced to a QT tank at 1.019 SG, to match the source tank from the vendor. Over the course of 48 hours, the SG is lowered to 1.009 and held stable. Let's assume the fish came in with an ich infection (trophonts attached). After 10 days of hypo, the fish is moved to another clean tank at 1.009 SG. This tank is raised to 1.024 SG over 5 days. The fish is then introduced into the display tank free of any possible infection.

Alternate Scenario w/copper: Everything is done the same way as above, except there is no waiting period for increasing and decreasing SG. The fish is moved directly to the display tank after 10 days.

What am I missing here? This would allow for a 10-15 day QT, not the 30-45 usually recommended. The theory behind this is as follows:

• The trophont stage where the parasite feeds on the fish lasts 3-9 days, thus even if the treated fish was infected immediately before introduction into QT, the trophont would fall off within the 10 day window.
• All free-swimming theronts are neutralized by the hypo/copper before they can re-attach to the fish, thus they cannot reinfect the fish within the 10 day window.

If all of this holds true, I see no way the fish can be infected leaving the QT after 10 days. I know I must be missing something, can you please let me know what it is? Perhaps the trophont phase can last much longer than 9 days? Perhaps we cannot be sure that all theronts will be neutralized by the treatment?

@Jay Hemdal @vetteguy53081 or others, what am I missing?

 

[vetteguy53081]

Posting a theoretical question for the fish docs. For the purposes of this scenario, please assume the following:

• Crypto is the only parasite I am addressing
• The QT is 1.009 hypo, although copper could also be subbed in this scenario
• The tank has NO preexisting infection - assume the tank is clean when the QT is started
• This is a QT scenario, not a treatment scenario

Scenario: Fish with no signs of ich infection is introduced to a QT tank at 1.019 SG, to match the source tank from the vendor. Over the course of 48 hours, the SG is lowered to 1.009 and held stable. Let's assume the fish came in with an ich infection (trophonts attached). After 10 days of hypo, the fish is moved to another clean tank at 1.009 SG. This tank is raised to 1.024 SG over 5 days. The fish is then introduced into the display tank free of any possible infection.

Alternate Scenario w/copper: Everything is done the same way as above, except there is no waiting period for increasing and decreasing SG. The fish is moved directly to the display tank after 10 days.

What am I missing here? This would allow for a 10-15 day QT, not the 30-45 usually recommended. The theory behind this is as follows:

• The trophont stage where the parasite feeds on the fish lasts 3-9 days, thus even if the treated fish was infected immediately before introduction into QT, the trophont would fall off within the 10 day window.
• All free-swimming theronts are neutralized by the hypo/copper before they can re-attach to the fish, thus they cannot reinfect the fish within the 10 day window.

If all of this holds true, I see no way the fish can be infected leaving the QT after 10 days. I know I must be missing something, can you please let me know what it is? Perhaps the trophont phase can last much longer than 9 days? Perhaps we cannot be sure that all theronts will be neutralized by the treatment?

@Jay Hemdal @vetteguy53081 or others, what am I missing?

Your plan is in Agreement and should be effective with cryptocaryon

 

[Jay Hemdal Verified Community Expert]

Posting a theoretical question for the fish docs. For the purposes of this scenario, please assume the following:

• Crypto is the only parasite I am addressing
• The QT is 1.009 hypo, although copper could also be subbed in this scenario
• The tank has NO preexisting infection - assume the tank is clean when the QT is started
• This is a QT scenario, not a treatment scenario

Scenario: Fish with no signs of ich infection is introduced to a QT tank at 1.019 SG, to match the source tank from the vendor. Over the course of 48 hours, the SG is lowered to 1.009 and held stable. Let's assume the fish came in with an ich infection (trophonts attached). After 10 days of hypo, the fish is moved to another clean tank at 1.009 SG. This tank is raised to 1.024 SG over 5 days. The fish is then introduced into the display tank free of any possible infection.

Alternate Scenario w/copper: Everything is done the same way as above, except there is no waiting period for increasing and decreasing SG. The fish is moved directly to the display tank after 10 days.

What am I missing here? This would allow for a 10-15 day QT, not the 30-45 usually recommended. The theory behind this is as follows:

• The trophont stage where the parasite feeds on the fish lasts 3-9 days, thus even if the treated fish was infected immediately before introduction into QT, the trophont would fall off within the 10 day window.
• All free-swimming theronts are neutralized by the hypo/copper before they can re-attach to the fish, thus they cannot reinfect the fish within the 10 day window.

If all of this holds true, I see no way the fish can be infected leaving the QT after 10 days. I know I must be missing something, can you please let me know what it is? Perhaps the trophont phase can last much longer than 9 days? Perhaps we cannot be sure that all theronts will be neutralized by the treatment?

@Jay Hemdal @vetteguy53081 or others, what am I missing?

The trouble is that neither hypo nor copper are effective at killing the cryptocaryon tomonts (resting stage). Since you can’t see these, you’ll never know if some got caught up in the net when you moved the fish to the new tank. The 30 day time frame helps ensure that the tomonts are kept from releasing theronts long enough so that they are rendered non-infective.

 

[Gone Reefin’]

I see. That is one part I missed. It appears the tomonts encyst in the substrate and rocks, if these are avoided in netting than theoretically this could be avoided?

Your response also has me thinking about the protomont stage (falling off fish). Perhaps this is a risk during netting also (in the water). However, it looks like this stage is short.

I suppose if tomonts can get stirred up with normal current and become waterborne, this would be a risk during capture. Perhaps a triple rinse between netting and introduction into the display tank….

 

[christinna77]

Posting a theoretical question for the fish docs. For the purposes of this scenario, please assume the following:

• Crypto is the only parasite I am addressing
• The QT is 1.009 hypo, although copper could also be subbed in this scenario
• The tank has NO preexisting infection - assume the tank is clean when the QT is started
• This is a QT scenario, not a treatment scenario

Scenario: Fish with no signs of ich infection is introduced to a QT tank at 1.019 SG, to match the source tank from the vendor. Over the course of 48 hours, the SG is lowered to 1.009 and held stable. Let's assume the fish came in with an ich infection (trophonts attached). After 10 days of hypo, the fish is moved to another clean tank at 1.009 SG. This tank is raised to 1.024 SG over 5 days. The fish is then introduced into the display tank free of any possible infection.

Alternate Scenario w/copper: Everything is done the same way as above, except there is no waiting period for increasing and decreasing SG. The fish is moved directly to the display tank after 10 days.

What am I missing here? This would allow for a 10-15 day QT, not the 30-45 usually recommended. The theory behind this is as follows:

• The trophont stage where the parasite feeds on the fish lasts 3-9 days, thus even if the treated fish was infected immediately before introduction into QT, the trophont would fall off within the 10 day window.
• All free-swimming theronts are neutralized by the hypo/copper before they can re-attach to the fish, thus they cannot reinfect the fish within the 10 day window.

If all of this holds true, I see no way the fish can be infected leaving the QT after 10 days. I know I must be missing something, can you please let me know what it is? Perhaps the trophont phase can last much longer than 9 days? Perhaps we cannot be sure that all theronts will be neutralized by the treatment?

@Jay Hemdal @vetteguy53081 or others, what am I missing?

I asked the same question a while back: https://www.reef2reef.com/threads/current-quarantine-protocol.825055/post-13990987. Here's a post from kboogie that goes more into depth: https://www.reef2reef.com/threads/current-quarantine-protocol.825055/post-13989308

TLDR was that 14 days of copper + transfer may fail because it assumes copper is 100% lethal to theronts and that no viable parasites survive long enough to restart the cycle. Not sure about hypo though.