The Theraphosidae are the most famous and diverse mygalomorph spiders, and include some of the largest arachnids on earth. Their unique defense mechanisms, predatory tactics, reproductive strategies and ecological adaptations are displayed by a wide range of terrestrial, burrowing and arboreal species. These arachnids are familiar to the general public thanks to horror movies and a growing interest in tarantulas as pets; however, scientific information on the group is scattered throughout the literature and not easily available. This book reviews all major aspects of New World Theraphosid tarantulas and provides in-depth information on their evolution, taxonomy, behavior, physiology, ecology, reproduction, conservation and biogeography. As a comprehensive guide to the biology of tarantulas, it will appeal to researchers, students and terrarium hobbyists alike.