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Sex ratios was new book

Hi Folks,

I am not sure that we will ever find a magic bullet for killie sex ratios.
Killies come from so many different environments that it is likely that
different species have different triggers.  For fish which breed all year
long it might be a good idea to use temperature for example if there are
seasonal temperature changes in their environment. Females are born in the
cool seasons and males in warm ones. Over the course of a years time there
should be roughly an even distribution of both sexes. But what about
annuals? An unusually cool rainy season would produce all females or males
and so much for the species.  This would also be true of killies which are
born seasonally such as some North American killies which all seem to be
born in spring. Or how about those killies which come from areas where the
temperature never varies?

Killies have been around a very long time. They are supremely adapted for
their niche environments. I think that we will find that different killies
have different sexing mechanisms.

This is certainly not to say we can't screw up the sex ratios by raising the
fish in water conditions which they would never encounter in their native
environments. It is very unlikely that in its native environment a diapteron
will encounter 79 degree water with a ph of 8.9 and a tsp of salt per
gallon. Put in such an environment if the fish were to survive at all and
even more unlikely lay eggs should we be surprised if the sexing mechanism
were to get screwed up? I think that some of the single sex hatches have
more to do with fish being kept in water they are not adapted to than any
natural sexing mechanism.  In the case of the spoorenbergi maybe in their
natural environment they lay their eggs in shallow water warmed by the sun
to over 78 degrees daily and this temperature is required for correct egg
development. Keeping them cooler screws up the sexing mechanism and produces
females.

Just a thought for discussion....

Peace,

~RJ~

-----Original Message-----
From: owner-killietalk at aka_org [mailto:owner-killietalk at aka_org]On
Behalf Of Frauley Elson
Sent: Thursday, February 21, 2002 8:59 PM
To: killietalk at aka_org
Subject: Re: new book


The Romer experiment on sex ratio in apistos is now standard fare in the
dwarf cichlid hobby. As far as killies go, it does suggest determination
of sex after hatching, but it doesn't necessarily transfer well, at
least to cooler water killies.

RuevenM at aol_com wrote:

>      There is a wonderful new book available that might be of real help to
> people experiencing sex ratio problems with killies. The book deals with
> Apistos, but its author has conducted a series of tests on sex ratio and
the
> effect temperature and pH have on the determination of sex in fry.


(BTW, has anyone
> been using the almond tree leaves in tanks? They do not last long but boy
do
> they drop pH and soften water -- if it is rather soft and neutral to begin
> with. They also leak tannins much faster than peat and supposedly have
> medical properties.)

I've been using 'wild almond' leaves for a couple of months now. They
stopped a bacterial infection in a group of young killies, really
impressively, so i suspect an anti-bacterial effect(or a miracle). And i
find that a tiny piece in the egg containers seems to help. I am
skeptical, but more and more impressed.
Gary
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