How about female choice? In nature there should be enough room for the
females to ellude all frustrated males of different species. In a tank
situation less possible for the female to run away. (maroon you on a small,
deserted island with a normally uncoperative member of the opposit sex, and
given time see what heppens ;-) Similar with cryptic and sibbling species of
hawaiian Drosophilla. Seems that morphologically they are very similar and
physically possible to interbreed and do so in the lab (some have lock and
key genetalia and this prevents interbreeding all together), but in nature
very specific behavioral cues are lacking and hence the species rarely (but
do) interbreeed. Perhaps your studies will show that the relationships
between maccullochi and nigrans divered a longer time ago as compared to the
divergence of the tris and splendida groups....
MTF
Imagine your day job
> being snorkling in warm creeks observing rainbowfishes spawning up on Cape
> York or somewhere similar!
>
> Tootles
> Peter