Pipefishes, members of the family Syngnathidae; closely related to seahorses; occur in freshwater, estuarine & marine habitats; about 230 known kinds of pipefish, 80 percent in region bounded by northern Red Sea & Pacific Coast of the Americas. Some spectacular varieties are easily recognized, but others are difficult to identify. "State of the art" treatment of nomenclature & taxonomy of 47 genera, 175 species & 7 subspecies recognized by author in Indo-Pacific region. Identification explained; keys provided to genera of the family Syngnathidae & subordinate taxa of Indo-Pacific pipefish. Synonymies, diagnoses & distribution data given for Indo-Pacific taxa, supplemented with information on habitat, size at maturity, intraspecific variation, etc. Outline of species composition of selected Indo-Pacific zoographic regions; notes included on Atlantic Ocean pipefish fauna. 263 figures, including 63 maps, 283 B&W photos.