Re: NANFA-L-- Het formosa sex

Scott Davis (
Tue, 4 Jul 2006 09:15:18 -0700 (PDT)

A couple of weeks should do. How about administering a preventative application with one of the commercial internal parasite treatments? Those should get many of the external parasites on the way in.

Of course, if you just left your formosa in the tub for a month or two with a resident population of Daphnia (or judicious feedings of mossie larvae) you probably would have your young females anyway.

I too have noticed disappointing returns in outdoor tubs if supplemental feedings aren't given and if the population density is very great. I'm sure someone could chart the population growth with X being population and Y either being space per fish or feeding.

Like you, I see more males. I wonder if - for myself - more partial water changes, even outside, are in order. It may be with some livebearers, that males are more abundant in order to make up for predation of conspicuously courting males.

If the water is appropriate and food abundant, gender differences can somewhat adjust in the next generation.

All the best!

Thorn Creek drainage in the mighty Calumet basin

James E Newville <> wrote: On Mon, 3 Jul 2006 12:41:21 -0700 (PDT) Gerald Pottern
> I see the same thing in my outdoor tub - few if any
> young female Het formosa-in-the end of summer.
> Indoors i get maybe 1/3 females, 2/3 males.
I'm think that since I have only 3 females, I should collect some more.
How long should I quarantine the newcomers before adding any to my
existing population? Thanks
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