No environment on Earth imposes greater physical and biological constraints on life than the deep oceanic midwaters. Near-freezing temperatures, the absence of sunlight, enormous pressure, and a low food supply make habitation by any living thing almost inconceivable. Yet, 160 species of anglerfishes are found there in surprising profusion. Monstrous in appearance, anglerfishes possess a host of unique and spectacular morphological, behavioral, and physiological innovations. In this fully illustrated book, the first to focus on these intriguing fish, Theodore W. Pietsch delivers a comprehensive summary of all that is known about anglerfishes - morphology, diversity, evolution, geographic distribution, bioluminescence, and reproduction.