Covering some 400 species, the authors (former co-editors of Ocean Realm magazine and co-founders of the Reef Environmental Education Foundation) present a guide that is designed to aid divers in the identification of fish found along the Pacific Ocean reefs off the coastline ranging from Baja, California to the Central American country of Panama. They have organized the material into "identification groups" that are based upon easily recognized features such as shape, swimming style, and color. Full color photographs are included, often depicting the different life-phases of individual species. In addition to general descriptions and the photographs, entries provide information on size, depth range, abundance and distribution, habitat and behavior, and reactions to divers.