Book excerpt: Addressing the numerous gaps in current information, Target Organ Toxicology in Marine and Freshwater Teleosts is an essential resource for researchers and professionals in aquatic toxicology and environmental risk assessment. All the chapters are written by researchers who are internationally recognised for their work in mechanistic aspects of aquatic toxicology. Each chapter focuses on a specific target organ or physiological system and describes how various agents disrupt the normal physiological system and processes. This volume is devoted to specific organs with coverage of the gill, kidney, skin, liver and gut. The companion volume, Systems, provides coverage of toxic effects in the central nervous, immune, neurobehavioural and reproductive systems as well as describing general mechanisms of toxicity.