Mister Gardener wrote:

When I posted the link to Maine's official list of allowed and banned
species a few weeks ago, several people expressed disbelief that the
Jack Dempsey has been added to the list of banned imports. How, many
people asked, could a Jack Dempsey be a threat, no way could one
survive a Maine winter. I asked the inspector about this and he told
me that Jack Dempseys were found to have survived more than one winter
in the state of Connecticut, whose climate can be just as harsh as
southern Maine. Amazing.

He "said" that, but I still maintain that it's no more than a suburban
legend. There's no documentation available online, and the one source I
was able to find for you implicitly stated that they have not been
naturalized.
--
derek