Xenopus, the African clawed frog, is one of the three most widely cited vertebrate animals in the biological literature, yet almost all knowledge is based on laboratory experience of a single species, Xenopus laevis from South Africa. Despite the occurrence of these frogs in habitats ranging from rainforest to semi-desert and from lowland swamps to alpine lakes in sub-Saharan Africa, the rest of the genus was until recently considered relatively uniform and uninteresting. During the past twenty years, field research has transformed our knowledge of these animals in their natural environment, and currently seventeen species are recognized. This book is the first attempt to describe their biology and natural history. The first five chapters cover systematics, ecology, distribution, and species interactions. The second section covers behaviour, sensory perception, and development. The next section focuses on infections and defence, followed by a final group of chapters on evolutionary and phylogenetic aspects. The aim of this volume is to provide a reference work for researchers working with Xenopus in the lab and to highlight for them and others the potential of Xenopus for future work in evolutionary biology, genetics, behaviour, immunology, parasitology, and ecology.