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The Thyasiridae is one of the most species-rich families of bivalves in the deep-sea areas of the northern Pacific Ocean. Many thyasirid species form abundant populations in these regions and play an important role in the functioning of deep-sea benthic communities. However, most of these deep-sea thyasirid species have not been identified and many of them are new to science. Based on the material of bivalves collected by eight deep-sea expeditions in the northern Pacific Ocean during the period from 1954 to 2016, three new species of the genus Axinulus (Axinulus krylovae sp. nov., A. alatus sp. nov., and A. cristatus sp. nov.) are described from the Kuril-Kamchatka and Japan trenches, the Bering Sea, and other deep-water regions of the northern Pacific Ocean (3,200-9,583 m depth). The new species are distinguished due to a unique and complex sculpture of the prodissoconch, including tubercles and numerous thin folds of varying length and shape, as well as due to a thickening of the shell in the adductor scar areas, thus rendering the scars raised above the inner surface of the shell. Comparisons with all species of the genus Axinulus are provided. [ABSTRACT FROM AUTHOR]

Results of experimental studies of the field of currents in the shelf zone of the Sea of Japan are discussed. The studies were carried out in 2001–2002 near the Gamov Peninsula, in the region of the acoustical-hydrophysical site of the Il'ichev Pacific Oceanological Institute (Far East Division, Russian Academy of Sciences). The purpose of the studies was related to the problems of developing the systems for long-term remote sensing of the climatic variability of the sea medium and for acoustic tomography of the dynamic processes in a shallow sea. In the experiment, combined acoustic transmitting and receiving systems (transceivers) and complex phase-manipulated signals with a carrier frequency of 2500 Hz were used. The velocities of currents calculated from the acoustic data agree satisfactorily with the velocities measured by standard methods of oceanography. [ABSTRACT FROM AUTHOR]