Quote Originally Posted by John View Post
Given that Pyxicephalus adspersus and P. edulis lay eggs in markedly different fashions, I think hybridization is at least very difficult, if not impossible.

I wouldn't completely rule it out though, sometimes frogs that that you wouldn't suspect can still successfully hybridize and in some cases those hybrids are even fertile. For example in toads there has been at least one genetically documented case of a wild natural hybrid between a woodhouse toad and a Colorado river toad, and also hybrids between wooodhouse toads and red spotted toads(which have somewhat different egg laying modes since red spotteds lay eggs individually and woodhouse lay in strings). Of course in those cases the occasional hybrids either are not fertile or don't do as well as the parent species or else gene flow would have created a new "species" a long time ago.

It wouldn't shock me though if wild male edulis were able to breed with female adspersus in areas where adspersus was less common some time in the past and created a "species" with some characteristics of both.