The shelf of the Pacific Ocean occupies 5.7%, the continental slope 12.2%, and the ocean floor 82% of the entire ocean area. Taxonomically the ichthyofauna of the Pacific Ocean is richer than that of other oceans. About 25 families of fishes inhabit only the Pacific Ocean, about 35 families inhabit both the Pacific and Indian Oceans. The study is based on recent VITYAZ' collections and data discussed in Soviet and foreign literature. There are two major components of the pelagic ichthyofauna inhabiting the Pacific Ocean: the epipelagic group inhabiting the subsurface water layer to a depth of 100-200m, and the deepwater group inhabiting the deep and bottom water layers. The first part of the book discusses the epipelagic fishes and the second part discusses the bathypelagic fishes. (Author).