Dactylogyrus (gill fluke) hatching times and suggested treatment routine

[Manky Sanke]

I had a PM from Gary at Aurora Koi (Gazkoi) asking for information about the hatching times of the eggs and treatment routine for dactylogyrus (gill flukes). I answered his question and he suggested that I should post it in the forum.

First some general information for anyone who doesn't know:
Gill flukes are egg layers that attach themselves to the gills of fish where they feed on mucus, epithelial cells (gill tissue) and blood. None of the treatments that can be used to kill flukes already attached to fish or the free swimming larvae that have just hatched and are seeking a host will kill the larvae that are developing inside eggs which were laid before the treatment.

With that in mind, this was my reply:
"The time taken for the eggs of dactylogyrus to hatch is very dependent on temperature. It varies from about two days at 30°C, four days at 20°C and 19 days at 10°C. Hatching times at temperatures below 10°C can be up to several weeks. At normal summer pond temperatures, dactylogyrus become sexually mature and can begin laying eggs about seven days after hatching.

A good rule of thumb is to re-treat the pond six days after the first treatment because all eggs that were released just before the first treatment will have hatched but even the earliest ones won't yet have had time to mature and begin to release the next generation of eggs.

It makes sense to re-scrape after the second treatment to verify that the treatments were successful but make sure that any flukes you see after the second scrape are moving and don't be misled by the dead bodies that have been killed by the treatments but haven't yet dropped off which can take several days after they were killed."

[freddyboy]

I had a PM from Gary at Aurora Koi (Gazkoi) asking for information about the hatching times of the eggs and treatment routine for dactylogyrus (gill flukes). I answered his question and he suggested that I should post it in the forum.

First some general information for anyone who doesn't know:
Gill flukes are egg layers that attach themselves to the gills of fish where they feed on mucus, epithelial cells (gill tissue) and blood. None of the treatments that can be used to kill flukes already attached to fish or the free swimming larvae that have just hatched and are seeking a host will kill the larvae that are developing inside eggs which were laid before the treatment.

With that in mind, this was my reply:
"The time taken for the eggs of dactylogyrus to hatch is very dependent on temperature. It varies from about two days at 30°C, four days at 20°C and 19 days at 10°C. Hatching times at temperatures below 10°C can be up to several weeks. At normal summer pond temperatures, dactylogyrus become sexually mature and can begin laying eggs about seven days after hatching.

A good rule of thumb is to re-treat the pond six days after the first treatment because all eggs that were released just before the first treatment will have hatched but even the earliest ones won't yet have had time to mature and begin to release the next generation of eggs.

It makes sense to re-scrape after the second treatment to verify that the treatments were successful but make sure that any flukes you see after the second scrape are moving and don't be misled by the dead bodies that have been killed by the treatments but haven't yet dropped off which can take several days after they were killed."

Nice one syd. I for one did nt know all that.
So 6 days is a tip for retreating
Cheers mate fred

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[Gazkoi]

Excellent thanks Syd.

I know this topic has come up once or twice in here, so hopefully some clarity will be formed now.

As a slight ‘side question’, some products claim to be a once only treatment- would you expect those to penetrate the eggs?

Cheers

Gaz

I had a PM from Gary at Aurora Koi (Gazkoi) asking for information about the hatching times of the eggs and treatment routine for dactylogyrus (gill flukes). I answered his question and he suggested that I should post it in the forum.

First some general information for anyone who doesn't know:
Gill flukes are egg layers that attach themselves to the gills of fish where they feed on mucus, epithelial cells (gill tissue) and blood. None of the treatments that can be used to kill flukes already attached to fish or the free swimming larvae that have just hatched and are seeking a host will kill the larvae that are developing inside eggs which were laid before the treatment.

With that in mind, this was my reply:
"The time taken for the eggs of dactylogyrus to hatch is very dependent on temperature. It varies from about two days at 30°C, four days at 20°C and 19 days at 10°C. Hatching times at temperatures below 10°C can be up to several weeks. At normal summer pond temperatures, dactylogyrus become sexually mature and can begin laying eggs about seven days after hatching.

A good rule of thumb is to re-treat the pond six days after the first treatment because all eggs that were released just before the first treatment will have hatched but even the earliest ones won't yet have had time to mature and begin to release the next generation of eggs.

It makes sense to re-scrape after the second treatment to verify that the treatments were successful but make sure that any flukes you see after the second scrape are moving and don't be misled by the dead bodies that have been killed by the treatments but haven't yet dropped off which can take several days after they were killed."

[Manky Sanke]

Excellent thanks Syd.

I know this topic has come up once or twice in here, so hopefully some clarity will be formed now.

As a slight ‘side question’, some products claim to be a once only treatment- would you expect those to penetrate the eggs?

Cheers

Gaz

I won't disput a manufacturer's claim but does it specifically refer to treatments for gill flukes which lay eggs or is it for the same treatment when used for skin flukes which are live bearers?

[freddyboy]

Excellent thanks Syd.

I know this topic has come up once or twice in here, so hopefully some clarity will be formed now.

As a slight ‘side question’, some products claim to be a once only treatment- would you expect those to penetrate the eggs?

Cheers

Gaz

Nice one gaz
Fred

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[deejaysmi]

thanks for that Manky, very helpful

[big h]

Excellent advice.At least we arent all guessing now.Thanks

[smartin]

Thanks MS, that's good to know.... are skin flukes any different ie use the 6 day rule for them as well or are they different in there development cycle ? thanks Steve.

[freddyboy]

Thanks MS, that's good to know.... are skin flukes any different ie use the 6 day rule for them as well or are they different in there development cycle ? thanks Steve.

6 days steve. But also depends on tempreture. That's the way I read it mate.

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[Manky Sanke]

Thanks MS, that's good to know.... are skin flukes any different ie use the 6 day rule for them as well or are they different in there development cycle ? thanks Steve.

Skin flukes (gyrodactylus) are live bearers so the first treatment will kill the adults plus any newly born lavae whether they have attached as they leave the adult uterus and already begun to feed and develop into adults or have been washed off of the fish and are seeking a host.

[freddyboy]

Skin flukes (gyrodactylus) are live bearers so the first treatment will kill the adults plus any newly born lavae whether they have attached as they leave the adult uterus and already begun to feed and develop into adults or have been washed off of the fish and are seeking a host.

(gyrodactylus). I can t even pronounce that syd. Flukes is better . Me thinks


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[Maddog1]

Hi Syd, Sorry to bring this up again, But I've treated my pond for Gill Flukes yesterday with Standard Lenerx. And my pond is only 12,14 degrees. Would 14 day's be a good gap to kill the Lavae? Thank you Syd

[Manky Sanke]

Hi Syd, Sorry to bring this up again, But I've treated my pond for Gill Flukes yesterday with Standard Lenerx. And my pond is only 12,14 degrees. Would 14 day's be a good gap to kill the Lavae? Thank you Syd

Is this a memory test to see if I can remember what I wrote six years ago?? OK, I'm always up for a challenge so I'll give it a go.

Hatching times vary greatly between 12°C and 14°C so there isn't a standard time and the hatching rate of eggs from the same batch can vary a little anyway with a greater variation at lower temperatures than at higher temperatures.

At 12°C dactylogyrus (gill flukes) egg hatching isn't predictable but I would expect eggs to take between two to three weeks to hatch. The hatching rate becomes more predictable as the temperature rises so I would expect eggs to take about one week to hatch at 14°C.

Did I pass?

[Maddog1]

Hi Syd. Thank you for your reply. You have passed with honours. Gill flukes are a Nightmare. This year they got active really early. Probably around early march. I'm just wondering now, if I should have treated earlier. There's one I think treats down to 3 degrees. I know it's never adviceable, but I'm thinking of a shotgun treatment at the end of summer to knock them back. What are yours thoughts please Syd. Thank you

[davethefish1]

I battled gill flukes for years never eradicating them, just knocking them back.
I believe my shower was oxidising the medication so it was only partially effective, killing some flukes but not all.

What eventually fixed it for me was SV. i did a full dose twice 3 days apart. and it made a huge difference, like taking a sledgehammer to a walnut.
the fish never reacted to the medication at all, this was all done while running a large shower and the drum.
later on that year i replaced some pumps I removed the shower and installed a large K+ bed.

the next year i had a few flukes show up, not many, so i did one dose, planning on doing another the same as before,
but this dose hugely afffected the fish, clamped up sitting on the bottom not feeding, they were not at all happy.
And it took a month for them to recover, and return to normal feeding ect...
I belive this was due to the shower removed, so the medication strength wasn't reduced by oxidisation. and made it effectively a much stronger dose.

I haven't had fluke issues since but SV effectiveness can vary widely depending on your individual pond, and how quickly it nutralises the medication.
I would use SV again if i had to, but it would be a last line after failing every other medication as it can be a very harsh treatment varying pond to pond...

[Maddog1]

I battled gill flukes for years never eradicating them, just knocking them back.
I believe my shower was oxidising the medication so it was only partially effective, killing some flukes but not all.

What eventually fixed it for me was SV. i did a full dose twice 3 days apart. and it made a huge difference, like taking a sledgehammer to a walnut.
the fish never reacted to the medication at all, this was all done while running a large shower and the drum.
later on that year i replaced some pumps I removed the shower and installed a large K+ bed.

the next year i had a few flukes show up, not many, so i did one dose, planning on doing another the same as before,
but this dose hugely afffected the fish, clamped up sitting on the bottom not feeding, they were not at all happy.
And it took a month for them to recover, and return to normal feeding ect...
I belive this was due to the shower removed, so the medication strength wasn't reduced by oxidisation. and made it effectively a much stronger dose.

I haven't had fluke issues since but SV effectiveness can vary widely depending on your individual pond, and how quickly it nutralises the medication.
I would use SV again if i had to, but it would be a last line after failing every other medication as it can be a very harsh treatment varying pond to pond...

Hi Dave. Thank you for the reply. That just proves the effect the showers have then. There's no wonder people have to retreat after retreat. Times like this I wished I had some sort of heating.

[big h]

I don’t think it’s a bad idea to dose with sv and turn the pump off for a while subjecting the fish to the full dose

[smartin]

I battled gill flukes for years never eradicating them, just knocking them back.
I believe my shower was oxidising the medication so it was only partially effective, killing some flukes but not all.

What eventually fixed it for me was SV. i did a full dose twice 3 days apart. and it made a huge difference, like taking a sledgehammer to a walnut.
the fish never reacted to the medication at all, this was all done while running a large shower and the drum.
later on that year i replaced some pumps I removed the shower and installed a large K+ bed.

the next year i had a few flukes show up, not many, so i did one dose, planning on doing another the same as before,
but this dose hugely afffected the fish, clamped up sitting on the bottom not feeding, they were not at all happy.
And it took a month for them to recover, and return to normal feeding ect...
I belive this was due to the shower removed, so the medication strength wasn't reduced by oxidisation. and made it effectively a much stronger dose.

I haven't had fluke issues since but SV effectiveness can vary widely depending on your individual pond, and how quickly it nutralises the medication.
I would use SV again if i had to, but it would be a last line after failing every other medication as it can be a very harsh treatment varying pond to pond...

Hi Dave,

i hope your well mate, been a while siince we last spoke, just been reading your thread, i was wondering if my shower was effecting the strength of the medication, i have used Fluke P about 5 days ago now (day 4 of treatment) but today seen some spitting and flicking off the window and air dome... i could scrape again but pretty confident its fluke, i also treated with PP not long ago so whitespot etc would of been eradicated.... not sure how effective Fluke P is but i could see on day 1 most fish were twitching and flashing as the medication was obvioulsy irritating the flukes and things seemed much better but today looks like i am back to square 1..... i think i am going to turn off the shower after an hour of day 1 treatment so it gets some water at full strength flowing through it then isolate thepond completely for 12 hours so it get time to work at full strength.... might help? SYD what are your views on this matter regarding showers and medication, i think Dave is correct in his views, Fluke P being a liquid form is specific for shower set ups but unsure of its effectiveness... atb Steve

[Maddog1]

Hi Dave,

i hope your well mate, been a while siince we last spoke, just been reading your thread, i was wondering if my shower was effecting the strength of the medication, i have used Fluke P about 5 days ago now (day 4 of treatment) but today seen some spitting and flicking off the window and air dome... i could scrape again but pretty confident its fluke, i also treated with PP not long ago so whitespot etc would of been eradicated.... not sure how effective Fluke P is but i could see on day 1 most fish were twitching and flashing as the medication was obvioulsy irritating the flukes and things seemed much better but today looks like i am back to square 1..... i think i am going to turn off the shower after an hour of day 1 treatment so it gets some water at full strength flowing through it then isolate thepond completely for 12 hours so it get time to work at full strength.... might help? SYD what are your views on this matter regarding showers and medication, i think Dave is correct in his views, Fluke P being a liquid form is specific for shower set ups but unsure of its effectiveness... atb Steve

Hi Steve, I have read on sites etc. Fish Flash Around 5 days or so, after treatment. I've read that Fish will carry on flashing, not just for flukes, but from the injuries they have subtained from the flukes.Are you heated?