In comments on assortive association in F2 hybrid progeny, I did
not mean to imply that this phenomenon reduces the risk of introgression
when exotic fishes closely related to indigenous taxa are released to the
wild. In the case of Australia, I'm not sure what problem of this kind you
might be referring to. If the thought was that hobbyist rainbowfishes
might (or might not) pose a threat when released far from their populations
of origin, then I would say you still have a genuine concern on your hands.
Les Kaufman
Boston University Marine Program
Department of Biology
Boston University
5 Cummington Street
Boston, MA 02215
e-mail: lesk at bio.bu.edu
phone: 617-353-5560
fax: 617-353-6340