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Re: Sex Ratio "Experiment"
Wright Huntley wrote:
> What affects the ratio in one species often is not the same as in another,
> and in some is influenced by very subtle differences not easy to measure.
> How else does one explain the late Paul W.'s success in fixing Rivulus sex
> ratios by raising two per shoebox and virtually *always* getting pairs?
Once again I have to agree with Wright (on his killies, never his sig files...).
While my trials with zygaima are an old story for many on the list, they boiled
down to alkaline hardish (140ppm) water producing males (35m:1f), while soft
(but not necessarily acidic) water gave a closer to even sex ratio (6m:4f).
I tried the two fish in a tank/shoebox experiment and got all males in three
tries in moderately alkaline tapwater.
So, it suggests there are a lot of variables operating. The work is a neat
project for anyone maintaining a species over a longer period, but I suspect it
will go species by species.
That being said, my ogoense 80/24 also give more females in tap/rainwater mixes
than in straight tap. I haven't kept them long enough (only into the 3rd
generation) to have a pseudo-scientifically formulated opinion, but if that helps
someone, it may be worth floating.
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