> these is that if two animals are not the same species any offspring produced
> from these unions will be sterile - meaning no offspring can be produced.
That's a kinda old way of thinking that has been thrown out for many
organisms by the majority of folks. Rainbows are a good example of this
as how many of them won't cross and produce fertile offspring (or at
least we presume they are fertile). Yet does anyone doubt that there is
more than one species in the three main rainbow genera? Species
definitions are a mess and you won't find a universal one. It's all very
subjective and it differs between organisms often for very good reason.
> Has any one ever done a careful study to actually know what crosses look
> like? I know that the American Killifish Association has a whole subgroup
> and a register of known crosses. Should one be set up for rainbows - I'm not
> volunteering to do this . . . but would consider helping.
The Australians frown upon any crossing of rainbows as do the Yanks.
It's a pity that no one has conducted any controlled crossing as a lot
could be learnt from it, ie are all crosses fertile? Has anyone ever
tested that? It may well be that some of the NG fish won't produce
fertile offspring from crosses with Oz fish. Wouldn't that make a
potentially good counter argument to the ban on bows coming into Oz?
I have used cross in a general way, I haven't tried to distinguish
between what is a cross and a hybrid. :-)
Tootles
Peter Unmack