Distribution of the Notched fin eelpout Lycodes pectoralis (Zoarcidae) in the Northeastern Sea of Okhotsk during the Hydrological Summer

— For the first time, the data are presented on the distribution and size composition of the notched fin eelpout Lycodes pectoralis in the northeastern part of the Sea of Okhotsk during the hydrological summer. Its densest aggregations are located on the continental slope of Kamchatka between 52° and 56° N and in the western part of the TINRO depression, in a local area 56°–57° N. The range of the vertical distribution of L. pectoralis covers depths from 199 to 653 m, and the temperature range in which this species occurs is 0–2.3°С. High frequency of occurrence, average density and biomass of the species are typical for depths of 301–400 and 401–500 m at a temperature of the near-bottom water of 1.0–2.0°С. Based on a critical analysis of the literature data and the fact that L. pectoralis is predominantly confined to the habitat in the waters of the unique intermediate water mass of the Sea of Okhotsk, it is suggested that the species is endemic to the Sea of Okhotsk.