Hi Angus:

Sorry for not responding sooner. I looked through my African amphibian field guides and could not find any reference of X. laevis having large black spots on the underside. So, I have no explanation for the spots. Just keep a close eye on the spots. There is only one species of southern African Xenopus that has spots on the belly and on the underside of the legs - X. petersii, but they are found only in Namibia, Angola, Botswana, Zambia and northeast into Tanzania.

Photo xeno3.jpg is your typical X. muelleri. The key is the subocular tentacle just under the eye. Muelleri's tentacle is very long. I have never seen a pattern as in photo xeno2.jpg. That's my favorite

The age of sexual maturity for laevis is about 9 months for females and a year for males. You will find that muelleri isn't as large as laevis. Males will develop thick "nuptial" pads and the cloaca (vent) of the female will be swollen.

The call of X. laevis is quite complicated. The male has at least three distinct calls and the female has two. It appears that the female determines how long or short the male's advertisement call is. The male will call first, if the female likes him, she will give a long rap with excites the male. If the female is not interested, she will give a slow tick and the male will abruptly stop calling. These duets can be quite loud. Mine like to call in the twilight hours, just before sunrise and just after sunset.