Species composition and distribution of Zoarcidae in the northern part of the Sea of Japan from the data of trawl surveys

Species composition, ratio, distribution, and size composition of Zoarcidae on the shelf and the upper part of the continental slope of the northern part of Japan at depths of 5 to 700 m were analyzed on the basis of four trawl surveys. In the studied area, nine species of Zoarcidae were found: Bilabria sp., Bothrocara hollandi, Davidijordania lacertina, Lycodes japonicus, L. nakamurae, L. cf. yamatoi, L. tanakae, L. toyamensis, and L. cf. ushakovi. Data on catches, density of distribution at different depths, and size composition are listed for each species. Four species: B. hollandi, L. tanakae, L. nakamurae, and L. cf. yamatoi have the greatest biomass and numbers among zoarcids in the northern part of the Sea of Japan. It was shown that zoarcids from the northern part of the Sea of Japan, similar to most demersal fish, perform seasonal migrations from the depths of 200 to 500 m, which they inhabit in the summer period, to depths larger than 400 m in the winter. It was found that the most common species of Zoarcidae (B. hollandi, L. tanakae, L. nakamurae, L. cf. yamatoi, and L. toyamensis) dwell mainly in waters of the intermediate water mass and the upper part of the Sea of Japan water mass. These species are abundant at depths larger than 200 m, which permits assigning them to a mesobenthal ecological group. All of the studied species of Zoarcidae from the given region are stenothermal—the temperature range of their habitation is below 2°C, as a rule, from 0.3 to 2.5°C.