Do triploids ever have spawn in them?

11foot5

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Maybe this is a very silly question. I hardly ever kill fish, one a year maybe if bleeding etc. Took home a nice rainbow this year only to find it full of spawn (September time?). I thought triploids were sex neutral, but there again I think I read years ago that they’re all female and infertile, or there’s no males so breeding can’t take place? Can anybody shed some light on this spawn in fish thing!
 

Rob Edmunds

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I was told that the process to make trout "Triploid " ( exposing the eggs to mild radiation) is only around 75-85% effective....

I'm not sure if the figures above are correct, or even if the process uses radiation......

On that basis best to ignore everything in this post 👍👍😁
 

11foot5

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Thanks guys, have you experienced the same? I.e. caught a “triploid” with spawn in it?
 

aenoon

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I was told that the process to make trout "Triploid " ( exposing the eggs to mild radiation) is only around 75-85% effective....

I'm not sure if the figures above are correct, or even if the process uses radiation......

On that basis best to ignore everything in this post 👍👍😁
Mild radiation is not an option!
Two main methods, one is the heat-shock method that warms just-fertilized eggs to retain a normally expelled chromosome, creating the sterile triploid.
The other is pressure treatment.
Both methods are forcing the egg to retain a chromosome that is normally ejected during egg development. ... With 3 chromosomes the trout is sterile and cannot reproduce.
So no, a triploid will not have developed spawn, aka eggs.
However, is not 100% when applied, some fish do manage to produce eggs even after triploiding process.
Indeed, is often noted that triploided hens do have tiny egg sacs, by tiny, sacs of half an inch or so.
 

Oddball29

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I had one about this time last year at syon park, bright red cheeks and stuffed with eggs so much so they were squirting out as I was unhooking it
 

loxie

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These days you would expect 98% + or - 2%. I don't think anyone uses heat anymore it's all pressure. There was an unprecedented shortage of restocking (all triploid) fish last summer and autumn and an unsaleable surplus of table (all female) at the same time. A cynic might think that that situation could have led to more females in ponds than might normally be the case.
 

loxie

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Rainbows dont produce eggs in sept/oct, you sure it was not a brownie?
These days the strains are all a bit randomised. September is very very early for non photoperiod fish though.
 

aenoon

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yes i had one last year, id guess sept/oct, full of eggs
These days you would expect 98% + or - 2%. I don't think anyone uses heat anymore it's all pressure. There was an unprecedented shortage of restocking (all triploid) fish last summer and autumn and an unsaleable surplus of table (all female) at the same time. A cynic might think that that situation could have led to more females in ponds than might normally be the case.
Even at that figure, still means 2 in every 100 might produce eggs, extrapolate to large stocking of waters, 20 in every 1000, 200 in every 10000, etc etc, so it is likely some folks might catch one that is egg bound, but that will only be late feb through to april.
 

ed_t

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100 % stocked rainbow, reservior
could have been oct/ early nov
Couple of years ago syon had several stockings that were mostly gravid. More fish full of roe than not.
 

pentlandflyman

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Used to get fish full of spawn all the time but it was always at the day ticket waters that stocked cheap fish, they started spewing eggs as soon as you landed them. I haven't had one in a long long time though so I'm guessing the process is totally different nowadays. I'm sure there are/were a few waters that rainbows successfully spawned in...portmore was one I think 🤔
 

jerryrum

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