Hello Mike.
There are only two species of dwarf clawed toads, one of which has two subspecies. The only other similar species is Pseudhymenochirus merlini from West Africa, which has probably never been exported. The smallest species of Pipa (P. parva) is three times the size of any Hymenochirus and no Pipa have webbed front feet.
As for which one you have....they are very difficult to tell apart and I'm in unchartered waters here. I THINK H. curtipes is stockier, has shorter limbs and shorter, stumpier fingers. If I'm right, the ones around at the moment belong to this species and they are in great shape. I bought a group of five and they haven't stopped calling, amplexing and spawning since I had them about a month ago. In the past imporations were thin and in poor shape. I think these were boettgeri but I could be wrong.
I hope this helps.
Chris
PS If you read German there's a great book called 'Amphibien im Aquarium' by Hans-Joachim Herrman, with lots of information on aquatic frogs (and caecilians and salamanders,of course). Published 1994.
