Re: [RML] Inbreeding

caryho at ix.netcom.comREMOVE_TO_REPLY
Mon, 02 Jun 1997 03:39:45 GMT

In The Dawn of the Third Age asaunders at mho.net (Aleksei Saunders) woke
me from my contemplation by writing:
> I've got a question, primarily for those of us in North America
>who don't have access to "new blood" all that easily, about the
>inbreeding of fish stocks.
> Do many of you that do rainbowfish breeding big time worry
>about back crossing your fish? (ie breeding parents to siblings, or
>siblings to siblings).
Yes we are worried about it, that's why we're developing the Species
Maintenance Program in America. This problem isn't unique to just
America, but exists in Europe and even Australia. Most of our stocks
came from small starter populations. Then again crossing fish of
differing population groups could cause even more problems.

> I just got some eggs from Chris and was wondering, if I'm breeding these fish,
> which are probably all from the same parental stock, am I doing a diservice to the
> idea of keeping good, pure strains going here in the states?

Are the populations developing a more homogeneous gene pool after
generations in captivity? Definitely the way we're keeping rainbows
and many other species in the hobby. This can be considered bad and
good. If the objective is to develop a stable captive population for
aquarium keeping, what we're doing is the way to go. That is unless we
fix in a negative allele and wipe out the population. Or lock in a set
of alleles creating a fish that looks nothing like the wild
population. Mainly we've attempted to limit this affect by group
spawning rainbows. This slows down the loss to the gene pool, but its
still occurring.
The present form of the Species Maintenance in America is the
presently forming Breeders Circles. The plan is to get groups of
individuals keeping each species and strain. They would work to insure
we have enough stock and diversity to continue the species in
captivity. This make take the form of working to develop a stable
homogeneous gene pool with some species or maximum genetic diversity
with others. I'm planning on formalizing our goals at the RSG San
Francisco Convention, but am presently looking for people willing to
commit to keeping species.

later
Cary Hostrawser
*please note the reply to address has been modified to
prevent automated junk mail.
Please delete "REMOVE_TO_REPLY" from the email message to respond to this email.

Minnesota Aquarium Society
http://www.mn-aquarium.org/

Rainbowfish Study Group Web Page
http://home.stlnet.com/~gwlange/rainbowfish.index.html/