Re: NANFA-L-- Old story, new twist?

Hold The Cow! (
Mon, 15 May 2006 10:24:34 -0400

After reading this post it got the critical thinking gears turning. I am
posting my comments as more a question, I guess. Perhaps Peter or Bruce can
comment more on this. Here goes....

In any given part of the world's aquatic habitats, did fish not evolve
because of certain habitat, climate, environmental conditions that were best
offered to them..hence they flourished in that part of the world.. Ex: cold
water streams and all they entail + time = darters. Warm water habitats and
all that entails these habitats, +time equals tropical species most suited
for that habitat, and so on.

Now, would it be possible that in the long run if North American habitats
were infiltrated with exotics, as many places are today, that while some of
these species may see a peak in their occupying the new habitat by
outcompeting for food, etc... that even these same exotics will be following
a road to demise when they have eaten all the food, and end up dying off one
day because the new habitat they are now living in, does not provide all the
necessary ingredients that allowed them to evolve in their original region
in the first place....then, we end up with an environment with limited
numbers of species.

Now keep in mind, I am giving these species a start in what would be
considered a relatively healthy habitat here. Now I understand that some
species may adapt and thrive where conditions are similar, but the overall
question is... is will they ultimately survive in places where they did not
evolve in the first place. Carp do, (but then again.. carp can live in my
toilet and survive!)but does this same rule apply for other species? Point
of all this... won't some exotics eventually wipe themselves out in areas
where they are introduced?

Rob Carillio
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