Subject: Re: NANFA-L-- Review of Suckers in North America
Moontanman at aol.com
Date: Tue Oct 12 2004 - 13:41:16 CDT
In a message dated 10/12/04 1:38:12 PM Eastern Daylight Time,
dlmcneely at lunet.edu writes:
> That's what we've done with domestic animals, fish included. And they
> don't fit the wild conditions that produced their ancestors.
> This probably applies less to modern captive breeding programs for
> threatened and endangered animals than it does for typical hatchery animals.
Ok, if I understand you correctly then it's not breeding in captivity that
makes the fry less likely to survive it's the breeding of multiple generations
of fish who in the wild wouldn't other wise have bred makes for fish that are
less able to survive over all. If I take this analogy further then adult fish
who are the result of many generations of breeding fish that were not required
to learn survival techniques if released into the wild would produce fry that
were less suited to survival than adult fish who grew up in the wild? Can this
effect also have an unintentional effect on the physical appearance of the
fish as well? This would be similar to the studies done of foxes bred in
captivity for their furs. It was found that in 12 (or a few more) generations of
breeding for foxes that were docile enough to be handled to make them easy to
raise. The animals lost much of their fox like appearance and became multicolored
with neotenic features that made them worthless as fur animals. Kind of a
catch 22 for the fur farmers who needed docile animals so they would be easy to
raise which made them worthless as furs. Another effect was a great fox like
pet animal! Now we need to find a technique that would weed out the slow fish so
the breeders would be more likely to produce fish fry fit to survive. Making
fit fish of a percentage higher than wild caught fish would produce would be
the "Holy Grail" of fish farming?
My futures so bright, I gotta wear shades!
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: Fri Dec 31 2004 - 11:27:44 CST