Crustaceans are increasingly being used as model organisms in all fields of biology, including neurobiology, developmental biology, animal physiology, evolutionary ecology, biogeography, and resource management. Crustaceans have a very wide range of phenotypes and inhabit a diverse array of environments, ranging from the deep sea to high mountain lakes and even deserts. The evolution of their life histories has permitted crustaceans to successfully colonize this variety of habitats. Few other taxa exhibit such a variety of life histories and behavior. A comprehensive overview of their life histories is essential to the understanding of many aspects of their success in marine and terrestrial environments. This volume provides a general overview of crustacean life histories. Crustaceans have particular life history adaptations that have permitted them to conquer all environments on earth. Crustacean life cycles have evolved to maximize fecundity, growth, and ageing, in a wide range of environmental conditions. Individual contributions contrast benefits and costs of different life histories including sexual versus asexual production, semelparity versus iteroparity, and planktonic larvae versus direct development. Important aspects of particular behaviors are presented (e.g. migrations, defense and territorial behaviors, anti-predator behavior, symbiosis).