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Re: only male fry
andei a pensar...
e se existirem genes anti inbreeding?
como o inbreeding é mau para a espécie pode haver genes que detectem quando
há muitas cópias iguais de genes.
Geralmente o inbreeding gera animais defeituosos, um gene que podesse
previnir isto faz sentido a nivel evolucionário, já que se os apistos se
reproduzirem em ambientes fechados e pequenos (charcos), pode ser útil um
gene deste tipo (mais alevins viáveis).
que achas?
se for uma ideia estúpida não mando para a lista...
:)
----- Original Message -----
From: "Nuno Prazeres" <nprazeres@vodafone.pt>
To: <apisto@v2.listbox.com>
Sent: Wednesday, December 03, 2003 7:36 PM
Subject: Re: only male fry
I read somewhere (maybe Romer) that very selected lineages tend to produce
skewed sex ratios and temp and pH become less of an issue in those
particular cases. If your friend's apistos are a result of intense selective
breeding this might explain the fact.
In my humble opinion your friend should try to spawn the apistos at 25C and
then during larval period lower one degree per day until it gets down to 22.
It might be helpful to move pH up a bit if it is too low. After about 600
hours over the birthtime temp can go up again because sex is formed. I am
basing this on reading material and not experience. Generaly the higher the
tem the more males you get. Is some species the same happens with pH but to
a lower extent aand the lower the pH is the more males you get. Since sex is
formed in teh first weeks and not determined at spawn time spawning
temperature can be confortably the very same.
Sorry for my mispell about m and micro Siemens. 1 milli = 1000 micro :-)
-----Mensagem original-----
De: owner-apisto@v2.listbox.com em nome de Dániel Gergely Faragó
Enviada: qua 03-12-2003 18:31
Para: apisto@v2.listbox.com
Cc:
Assunto: Re: only male fry
Hi,
Thanks for the answers. Though I am getting a bit confused. As live in
Europe TDS is not a common thing to measure. But we have gH and kH. So could
you tell me if there is a correlation between dH and gH. Now I have a total
hardness about 6-7° gH.
Second, if I get it right the rules Mike wrote do not apply as the water's
getting harder. So 7 microsiemens do not equal 7° dH (and 7° gH I suppose).
And last, if the temperature is kept under 26 C, what can be the cause of
having no females in the fry? (I ask this quite theoratically, as my friend
keeps telling me that temperatures couldn't rise higher than 26 C, but
egglaying happened in summer, and it is not easy to cool the water.)
Thanks again
Daniel Faragó
----- Original Message -----
From: Mike & Diane Wise <apistowise@bewellnet.com>
Date: Wed, 03 Dec 2003 09:53:41 -0700
To: apisto@v2.listbox.com
Subject: Re: only male fry
> Of course you are correct, Lee. That is why I wrote, "At low levels of
> total dissolved solids, 1 ppm TDS "roughly" equals an electrical
> conductivity of 1µS (microsiemen)." For almost all intended purposes in
> the soft water end of the hobby they can be considered equivalent. If
> you look at common inexpensive aquarium conductivity meters there is no
> difference in range between those measuring ppm TDS and µS/cm. They are
> the same instrument reading the same values. It probably would have been
> more accurate to say that 1µS roughly equals 1ºdH.
>
> Mike Wise
>
> LeeH920226@aol.com wrote:
>
> >In a message dated 12/2/03 11:32:56 AM, apistowise@bewellnet.com writes:
> >
> ><< TW I think there was a typographical error in the answer you received
> >
> >about ppm. At low levels of total dissolved solids, 1 ppm TDS roughly
> >
> >equals an electrical conductivity of 1µS (microsiemen). 1 mS
> >
> >(millisiemen), or 1000 µS, roughly equals 1000 ppm. It is not an unusual
> >
> >mistake on emails. Many do not know how to type a micron symbol (µ) &
> >
> >mistakenly use an "m" instead. The use of an "m", of course, represents
> >
> >"milli" in metric units. >>
> >
> >No, the TDS in ppm does not equal the conductivity in microsiemens/cm.
The
> >relationship is variable depending on the exact composition of the
dissolved
> >ions. It ranges from 1.5 to 2.0 /1 Conductance/TDS. Most common water
supplies
> >are at a 1.7/1.0 ratio.
> >
> >Lee Harper
> >Media, PA
> >
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> >
> >
>
>
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