Re: NANFA-L-- Fw: NAS Species Alert - Piaractus brachypomus

Subject: Re: NANFA-L-- Fw: NAS Species Alert - Piaractus brachypomus
Date: Thu Nov 04 2004 - 10:19:22 CST

In a message dated 11/4/04 10:49:10 AM Eastern Standard Time, writes:

> Though I am not aware of large bodied characins being included in this
> phenomenon, substantial numbers of breeding populations of tropical and
> subtropical species have been established in warm springs throughout North America.

Warm springs are not what I am talking about, warm springs are localized and
not a wide spread phenomenon.
  Livebearers are serious problems in many western U.S. and western Canadian
> locations.

Are the livebearers in question gambusia that have been established to combat
mosquitos? If so they are not aquarium releases. Gambusia are about the only
live bearer I can think of that would live in Canada.

 Tilapia have also become established in such places, though they mostly came

> from the aquaculture industry. Tilapia are major pests throughout S.
> Texas. For Pacu to proliferate similarly is not out of the question. And the
> deep South, S. Texas, Southern California and Arizona remain a part of the U.S.,
> so far as I know. Very soft, acid waters are characteristic of much of the
> Gulf and S. Atlantic coastal plains.

I live on the coastal plains you are talking about and the black water acid
streams here are very hard water not soft. I don't know why but it's true and
the temps are far too low for pacu everywhere but south Florida where they do
not have a breeding population either. Any pacu caught are just non reproducing
individuals and do not represent a successful invasion.

Exotics introduced anywhere are a major potential problem, and the aquarium
> trade and hobbyists are responsible to police themselves to prevent such
> problems. I was a big Pogo fan. You may be too young to remember the comic
> strip possum who ".... found!

I remember pogo, I'm not all that young (49) I wish I were. I agree that
release of exotics is always bad and should never be done, but almost all truly
harmful releases have been intentional to improve sport fish or some other
reason not connected to the aquarium hobby. As I said I cannot find any account of
a widespread population of any tropical fish in North America other than the
few places where the water temperatures stay warm and even in these places most
of the water is unsuitable for most soft water fish to breed in. I am open to
being disproved but I have really been researching every account I can find
and so far nothing has come up. Even where tropicals have established a
breeding population the effects of the tropicals hasn't been the catastrophic
disaster that was predicted in the early 70's. The aquarium hobby is being demonized
as the cause of massive habitat incursion but it's not true and I would hate
to see laws enacted that use this "common knowledge" as the reason to ban fish
keeping. As a group fish keepers have very little political pull and we could
be "run out of town on a rail" in a classic witch hunt just to make it look
like the powers that be are doing something to help the environment.


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: Fri Dec 31 2004 - 12:42:45 CST