[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: Sex ratios and water
I find the translations interesting I wonder if you could post more of them.
BREED YOUR FISH
TODAY MAN'S OVER
POPULATION IS KILLING
THE WILD SUPPLY
1819967 ICQ NUMBER
-----Original Message-----
From: Lilia Stepanova <ls691035 at bcm_tmc.edu>
To: killietalk at aka_org <killietalk at aka_org>
Date: Monday, July 13, 1998 10:49 PM
Subject: Re: Sex ratios and water
>
>Hi,
>Here is some info from book published in Russian (A.S.Polonskii
>"Soderjanie i razvedenie aquariumnih rib", 1991).
>
>"Temperature and chemical composition of the water can affect sex ratio
>in the fry of Cyprinodontidae. For example, at t=22-25 C most of the fry
>will be females, if the temperature is not constant, most of the fry will
>be males. At the same pH=6.0, E.dageti will have more female offspring
>(>90%) in the soft water (dH about 5 degrees), in the hard water (dH 24)
>about 90% of fry will be males. A.gabunense in the acidic water (pH 5.0)
>will give more females, at higher pH=6.5 - more males."
>
>Cheers,
>
>
>Lilia
>
>On Mon, 13 Jul 1998 elyj at liddellsapp_com wrote:
>
>> I was interested to read of Sam's experiment about pH and sex ratios.
>> Sam (or anyone else), did you try hatching the eggs in water of differing
>> pH and seeing what ratios you get? I think you said you hatched all eggs
>> in one type of water and then transferred the fry to different water. A
>> way to get some idea whether water conditions cause an actual shift in
>> gender or simply that certain conditions are better suited to one sex
might
>> be to monitor the percentage of eggs that hatch and grow to adulthood. If
>> a large number of eggs don't hatch, or don't hatch into vigorous fish, it
>> may indicate the latter is true. On the other hand, if a consistent
number
>> of eggs hatch under different conditions, but produce varying sex ratios,
>> it may indicate some gender shifting. Further, what about the possibility
>> that the water in which spawning takes place is a factor? That is, maybe
>> fertilization rates are higher for one sex under certain conditions. I
would
>> be interested in any thoughts anyone has on these topics. Of course, all
>> this may be totally off-base, but it would be interesting to know that as
>> well.
>>
>>
>
Follow-Ups: