Re: Extinction (was Re: Fp. robertsoni)

["Tyrone Genade" <Tgenade at AKAD_SUN.AC.ZA>]

On 1 May 2002, at 13:45, Edd.Kray at rf_doe.gov wrote:

> Isn't this why the
> australe, in the hobby for 50 years, is now runty and poorly colored
> vs wild stock ?

I don't know about your australe but mine are fit and vibrant. 
Locally we crossed the gold and wt strains 4 years back. The results 
have been very impressive both in regard to colour, size and egg 
production.

> I have this issue with my huberi strain...IS it better to let my aquarium
> strain die out, or to mix in genes from a slightly different locality?
> Tough decision for me.

I have no qualms about crossing out a new australe strain and an old 
one (I attempted to bring in some of the wild australe from Bill's 
stock lost year for this very purpose, granted I want to do it for 
genetic experiments regarding the spotless genes). If all the huberi 
appear to be huberi (unlike all the gardneri types) then why not? 
Just remember to lable the fish as huberi "Aquarium" or huberi "Type 
A x Type B" or something to keep track.

If I got wild dageti monroviea today I would cross them with my old 
strain in a few weeks time (quarantine...).

The point is: we can't tell the species from each other in many fish 
species while in others we can. A good example is the 
Chromaphyosemion and Fp. gulara/fallax/deltaense "complexes" vs the 
australe and calliurum species which are easily separated. We must 
just apply a little thought. Don't cross strains where there is any 
chance you are crossing 2 species and don't sell the fish for what it 
is no longer.

> Do we have a contradiction in principles in our breeding programs, the
> need for genetic diversity vs the desire to maintain our strains as
> distinct as they were from the wild? But then who is to say how
> distinct they were in the wild. Its the hobbyists guess.

We don't have a contradiction but rather a balance. For any 
conservation initiative we need a good size population size. 3 prs is 
not enough.
Further more, if the population is very hetrozygous it is easy to 
start subconsiously fixing strains ("that one doesn't look like the 
type picture... eat well Mr. Oscar") which is why genetic exchange is 
very important between breeders. I was just contacted by the 
alternatus maintenance group about an egg exchange. Personally I 
think an exchange every 3 generations would be adequate. If you are 
working with large populations (10 or say prs) then in 3 generatiosn 
you should have 99% of the original genetic complement. (You are 
going to loose genes and gene combinations regardless... it is called 
evolution.)

Good luck with your breeding plans.

Tyrone Genade
tyronegenade at yahoo_com
http://www.tyronegenade.0catch.com

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"No, the LORD has told us what is good. What He requires 
of us is this: to do what is just, to show constant love,
and to live in humble fellowship with our GOD." 
                                                Micah 6:8
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