Fishes of the World is a standard reference for the systematics of fishes. It was first written in 1976 by the American ichthyologist Joseph S. Nelson (1937–2011). Now in its fifth edition (2016), the work is a comprehensive overview of the diversity and classification of the 30,000-plus fish species known to science.
The book begins with a general overview of ichthyology, although it is not self-contained. After a short section on Chordata and non-fish taxa, the work lists all known fish families in a systematic fashion. Each family is given at least one paragraph, and usually a body outline drawing; large families have subfamilies and tribes described as well. Notable genera and species are mentioned, though the book does generally not deal with the species-level diversity. The complexities of the higher taxa are described succinctly, with many references for difficult points. The book does not contain any color illustrations.