Guppy Sex Debate, Please Join in ?

[jonny-5]

Please comment on this if you can....

So i was just looking at a few forums, YouTube videos & pages on this around the web & the debate is very mixed but wanted to know what others thought

Just for a bit of fun

I am wondering what you all think of the Temperature influence that supposedly affects newborn Guppy fry sexes?

So ive watched,read & read again comments about lower temps = more females & higher temps = more males, Then another clip on a forum said the lower temps = More males & higher temps = more females. Or is it just pure coincedence that the ratios vary?

Im just doing this for fun by the way, it really makes no odds to me
But just for the record my 1st,2nd,3rd batch of Guppy fry were mostly male kept at
P.H 7
Temp 25oC

Thanks for your comments

 

[Colin_T]

temperature doesn't make any difference to the sex of fish fry. pH does but not temp. In water with a high pH you usually get more males, in a low pH you get more females.

 

[GlosGraham]

Curious... Why / how does pH influence the gender?

 

[Colin_T]

No idea how/ why pH affects fish fry but every fish I have ever bred in water with a high pH (7.6+) has produced way more male offspring than females. If I breed the same fish in water with a neutral or slightly acid pH, I get way more females.

 

[jonny-5]

I have had a good look around the web & there isnt really any science behind the temperature theory. So probably is a myth then.
I was interested because i have 30 fry in my 10G breeder & there are 5 female out of that, The others in the main tank are far to young to sex yet

 

[Colin_T]

25C isn't warm either, it's right in the middle. I had my rearing tanks on 28C, but I also tested growth rates and sexes in water temperatures between 22 & 32C. Growth rates were best at higher temps and 28C was the most efficient with maximum growth rate and less power used by heaters to keep the water at 32C. The different temperatures didn't make any difference to sex ratios.

--------------------
It could be the food they are getting. Male fry are slightly bigger than females and have bigger mouths. This allows them to eat bigger food particles. Female fry regularly starve to death if they don't get small enough food during the first few weeks of life.

It could also be the males were simply fast enough to swim away and hide, so didn't get eaten.

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There might also be a genetic link with some fish naturally producing more male offspring. It happens in lots of animals and people so could happen in fish. I knew a few families where all their kids were boys and it had been like that as far back as the family could remember. And I have a friend who has 4 daughters and 1 son. I have 4 sisters and no brothers. My best friend from primary school had 4 brothers and no sisters.

I had a pr of budgies (parakeets) that used to produce all female offspring. They had 4-6 babies per clutch and every baby was female. This happened for years until one of the pr died. Other prs of budgies in the same aviary had even numbers of male & female offspring.

 

[jonny-5]

Hmm interesting, Suppose its a subject that could go on & on.
I really was not convinced that the temp could determine the sex of fish but i had doubts after seeing the videos. But now im more convinced its water chemistry that may have something to do with it. My P.H here is 7, So i guess im somewhere in ballpark for more Males. It would be interesting to see if the same Mom could produce more Females in a higher P.H though. I myself produce more females than males, having 3 daughters & 1 son, so my P.H must be high ?
Thanks for the replies

 

[fish48]

it's probably a combination of pH ; temperature and genetics
with a tank temperature of 20 C and a pH of 7.8 + my guppies produce more females

 

[Guyb93]

I’m no expert but it’s hard to believe I would assume they are like mammal and it’s the males fertilisation that dictates the sex

 

[Sgooosh]

idk ive only had 3 babies grow up to full size. but i dont think ph does anything

 

[jonny-5]

I have 50ish fry, 30 of them are 3,5 & 7 weeks now in a 10 Gallon, Still tons of room but looking at shipping some out soon.
I have another 20, 4 day old fry in a 30 Gallon with an army of Bronze Corys & the Guppy Mom and most of the older fry are male, these fish are kept at P.H 7 & constant 25oC so im gonna try raising the P.H when i have my 10Gall breeder back with some virgin young & see what happends

 

[Sgooosh]

I have 50ish fry, 30 of them are 3,5 & 7 weeks now in a 10 Gallon, Still tons of room but looking at shipping some out soon.
I have another 20, 4 day old fry in a 30 Gallon with an army of Bronze Corys & the Guppy Mom and most of the older fry are male, these fish are kept at P.H 7 & constant 25oC so im gonna try raising the P.H when i have my 10Gall breeder back with some virgin young & see what happends

oh i have a loot of babies all of a sudden. guess the fish got a little too happy

 

[jonny-5]

I used to breed the fancy guppys & endlers years ago but got fed up with the constant battle of water changes, feeding & cleaning poop up off the substrate, We had young kids back then so the fish thing was far too much hassle, So this time round i wanted to have another go. There were a ton of people local to me that used to take them off me on these forums, Dunno if they are still around? Would be handy if they were

 

[Sgooosh]

I used to breed the fancy guppys & endlers years ago but got fed up with the constant battle of water changes, feeding & cleaning poop up off the substrate, We had young kids back then so the fish thing was far too much hassle, So this time round i wanted to have another go. There were a ton of people local to me that used to take them off me on these forums, Dunno if they are still around? Would be handy if they were

haha i plan on selling guppies to lfss

 

[Sgooosh]

No idea how/ why pH affects fish fry but every fish I have ever bred in water with a high pH (7.6+) has produced way more male offspring than females. If I breed the same fish in water with a neutral or slightly acid pH, I get way more females.

my ph is like less than 8.5 or 8,2 or something and i have 2 female babies and 1 male tho. i will see what my new batch is. 5 babies