Originally posted by OrionGirl
There is not scientific difference between a toad and a frog. These terms are common reference to amphibians, and generally, toads are primarily terrestrial as adults while frogs are primarily aquatic, but this is a vagary of the language, rather than a biologically based separation.
A 5.5 gallon tank won't be adequate for a bullfrog, nor for the axolotl. They need at least 10 gallon, prefreably of water. The true ones will remain in their juvenile form their entire life, if not prodded into morphing into the adult form.