Re: [RML] pH and sex ratios
Gary Lange (gwlange at stlnet.com)
Wed, 4 Nov 1998 13:30:17 -0600
A while back I sent some info to the list concerning sex ratios in apistos.
Common "knowledge" had said that it was only pH that determined the sex ratios.
Uwe Rhomer showed without a doubt in a great paper that it was mainly
temperature. Is it temperature in bows - I don't think so BUT there are also a
lot of other factors that we might also not be observing. Ca/Mg or carbonate
hardness might very well play a part. I think most people raising a lot of
bows have observed if you avoid the extremes you get a pretty even ratio of
males and females. Some have suggested that low pH (low carbonates??) might
produce a higher ratio of males. Is there a "website"?? for these theories, if
it was unrelated to rainbowfish would it matter? Uh Dan not everything is on
the web and a lot of what is, is buyer beware. I think a great example of this
were all of the "opinions" on 24 hr light (for fry) that shot thru the RML
about a week back. That's a technique that has long been established by
accomplished breeders of cichlids, killifish, livebearers, guppies (they have
their own rules), and rainbowfish. A lot of those people that are busy
breeding the fish either aren't connected to the net or don't have the time to
bother with every question. The best way to find out good information is to
find a local aquarium club and talk to the well established breeders, if there
are any in that particular club.
Gary Lange
----------
> From: peter.unmack at ASU.Edu
> To: 'rainbowfish at pcug.org.au'
> Subject: RE: [RML] pH and sex ratios
> Date: Wednesday, November 04, 1998 11:19 AM
>
> On Wed, 4 Nov 1998, Simon, Dan wrote:
>
> > OK.....so what are these "theories" ? Can anyone point me to a web
> > site with the info ?
>
> It has been well known for sometime now that various factors in the
> environment can influence sex ratios. Many fish react differently to
> different things. It is extremely poorly documented, partly because
aquarists
> never keep good records, nor do many know how to perform a reliable
controlled
> experiment. Also, most do not have the resources to do this. I'm not so
sure
> that the reasons for this are well known either, they probably differ for
> different fish too. Best bet is trial and error. :-)
>
> Tootles
> Peter Unmack