I do not share Peter H.'s opinion that it doesn't matter
if crosses are sold. I have received so many phone calls
from people who had difficulties to determine their
species and couldn't bred them and I had to disappoint
the people because they bought crosses. More "simple"
(:-) some will hate me for that) aquarists want to breed
the fishes they buy than Peter thinks.
It is a must that crosses have to be labelled correctly.
Nobody minds if you sell red platyfish as platies, but
no dealer would have the idea to sell them as Xipho-
phorus maculatus "Rio Usumacinta" (this is a river
in Middle America).
In IRG we had our experiences with crosses, too. We found
that M. "hammeri" unfortunately seemed to be fertile
partially, however, it vanished as well as Glossolepis
boesemani (a cross between G. incisus and M. boesemani)
which was infertile. To sell infertile crosses is a kind of
fraud to all aquarists buying those and wishing to breed
them.
Another part of the discussion (however is bored on this
matter, should at least stop here). It doesn't matter if
a hybrid has developed naturally or by men release.
A species is "a geographically isolated self reproducing
community" according to Mayr and if the hybrids develop
into such one it's a new species. That's why the trifasciata
question in future will have to be discussed again (species
or varieties?).
Harro
harro.hieronimus at t-online.de