To followup; is the general contention that lower pH will produce more
males?
Bruce, you mentioned temperature as a factor. Would lower or higher
temperatures yield more males?
Currently I've been breeding at 80-83F with a water pH of about 7.3. My
estimate is about 60-65% females. However I found Wright's comment about
sex changing interesting. As I recall several years ago I had bred some
sailfin mollies and it was "clear" there were 5 females. A few months after
removing the males from the tank to my surprise there were now not one but 3
more males as evidenced by the gonopodium.
What sort of pH value would have an effect of sex? I have an aquarium with
6.7 pH versus the other 7.4 tanks. I'll try to breed them there.
Lastly, when selecting breeders is it more important to select good males or
good females? Does the genetic material get transferred 50/50 to the fry or
do the fry get more from either the male or female?
Thanks
Bill
----- Original Message -----
From: "Bruce Hansen" <bruceh at powerup.com.au>
To: <rainbowfish at pcug.org.au>
Sent: Sunday, February 11, 2001 2:15 PM
Subject: Re: [RML] Breeding questions
> G'day Bill
>
> We have had some discussion on this subject in the past ( you might find
> some of it interesting if you can find it ) but from memory there was
> faavour for both temperature and pH as modifying factors for sex ratios.
> Temperature seemed to come out as possibly more significant with evidence
> fromseveral specialty sub-groups of the aquarium hobby.
>
> Here in Australia some experienced hobbyists felt that higher pH increased
> female ratios and shellgrit substrates in UG filters were used with some
> success. Some genera seem more predisposed to be affected by this too e.g.
> Glossolepis.
>
> My suggestion would be to try for neutral (pH 7) and go from there - peat
is
> generally a safe way to go if you are trying to go "down".
>
> Regards,
> Bruce Hansen
> vicepresident - ANGFA Inc, ANGFA (Qld) Inc
> Please visit us at http://www.angfa.org.au
>
> ----- Original Message -----
> From: "william taylor" <wtaylor at austin.rr.com>
> To: <rainbowfish at pcug.org.au>
> Sent: Monday, February 12, 2001 5:19 AM
> Subject: [RML] Breeding questions
>
>
> > I've heard that pH affects sex determination. Is this true? If so,
what
> pH
> > ranges will produce more males? Also, if it is more acidic that
produces
> > more males, what are some good (easy, inexpensive) ways to get acidic
> water.
> > For instance, can I just add vinegar to lower pH (I'm assuming not, but
> > why?)? My local water is about 7.4 and I get about 60-65% females
> > (estimate).
> >
>
>