I was looking through the Nonindigenous Aquatic Species (NAS) Information
Resources web page;
and found another good reason not to release non-native species outside
of their habitat.
Red shiners, Cyprinella lutrensis, which had been infested with the
Asiatic tapeworm from grass carp, were introduced into Utah waters
containing Woundfin, Palgopterus argentissmus, an endangered native.
Heavy infestations of the tapeworm were found in Woundfin. apparently
the Red shiner is much more resistant to the tapeworm than the Woundfin.