The research outcomes of spatial and bathymetric distribution of dragon poacher Percis japonica are reported based on the bottom trawl surveys carried out in the Russian territorial waters in the Sea of Japan. The species can be found in the waters along the entire coastline. However, its spatial distribution pattern is variable. Thus, its distribution is sparse off the coasts of West Sakhalin, especially off the southern part of the island, while the species tends to congregate in the Peter the Great Bay and the Tatar Strait, where the locations of the species across these water areas remain almost unchanged throughout the year. With respect to the Northern Primorye Coastal Zone, the even distribution is typical for the entire water area, without any high congregation locations. Therefore, the dragon poacher can be found in wide ranges of depths and temperatures. However, its preferable ranges are substantially narrower. The highest values for available biomass resources are typical for the water areas off the Northern Primorye Coastal Zone.

Studies conducted in April−October showed that the Japanese sandfish Arctoscopus japonicus occurred in Peter the Great Bay in the near-bottom water layers at a depth of 1.5 to 550 m at a temperature of –0.2 to 16.5°C; however, distribution of the species varied during this period significantly. After a period of pelagic development, young fish with a length (FL) from 3.5 cm pass to the benthic mode of life and leave in July the coastal area. In summer, juveniles live at a depth of approximately 25–55 m; in the autumn, they spread over the shelf. Maturation of some individuals in the first year of life was not observed in the bay; it is typical only for the southern areas of the range. In the warm season, the majority of older fish adhere to the bathymetric range of 40–60 m and adjacent depths. In the autumn, before spawners approach the coast for spawning they descend into deeper waters and penetrate into the lower part of the shelf and onto the continental slope.

The results of research work conducted by the saury fishery vessel “NIKA 101” in the open waters of the North-West Pacific (NWP) and the South Kurile region during September- November 2014–2016 are presented. The distribution and migration routes of saury in the North- West pacific in 2014–2016 are shown. In 2014 and 2015, the main migrations of a large saury traditionally took place along the Kuril Islands along the Oyashio front and further south along the periphery of the South Kurile Eddy. The smaller and medium-sized saury migrated outside the Russian EEZ along the Northern Subarctic Front. The distribution and migration routes of the saury in the NWP in 2016 significantly differed from the distribution pattern in 2014 and 2015 In September-October 2016, the saury fishery was mainly conducted in the frontal zones of the oceanic and subarctic fronts where the surface temperature of water was 15–17 °C, unlike in previous years when saury basically occurred in waters with a temperature of 12–14 °C or less.

Abstract—The discovery of a spawning ground for Alaska skate Bathyraja parmifera in the northwestern part of the Sea of Japan (42°21′1″ N 131°16′6″ E), at a depth of 216–224 m and a bottom temperature of 1.0°C It is reported for the first time. Spawners and egg cases were found at the spawning ground.

Formation of the surface structure mechanism of the South Kuril waters in the last two years has undergone significant changes. Therefore, the “cold” type of hydrological conditions prevailed in the South Kuril area during August-November 2017. The surface water temperature was below the norm by 1–2 °C. On the contrary, the “warm” type of hydrological conditions prevailed in the South Kuril area during August-November 2018 and the water temperature in the area under consideration was 1–3 °C higher than the average for many years. Saury fishing in 2018, as in 2017, began in the second decade of August on the peripheral fronts of the Ask eddy and continued here until the second decade of September. At the end of September, the fishing area formed in the southwestern part of the EEZ of the Russian Federation and, unlike last year, it remained until the beginning of the third decade of October. The “warm” type of hydrological conditions causes this duration of the fishery. Saury moved outside the EEZ in late October. Fishing for sardines and mackerel began in mid-July 2018 and was carried out on the northern periphery of the eddy A’. However, at the end of October, unlike in 2017, fishing here practically stopped due to a decrease in the temperature drops at the peripheral fronts of the eddy caused by the high temperature of the surface waters of the Oyasio current. In late October — the first half of November in 2018, mackerel and sardine fished in high-gradient areas of the Northern Subarctic Front (NSAF) close to the eastern and southern borders of the Russian EEZ. During fishing season 2018, in contrast to the previous year, schools of sardines and mackerel remained much longer in the economic zone of Russia.

Впервые сообщается об обнаружении нерестилища щитоносного ската Bathyraja parmifera в северо-западной части Японского моря в координатах 42°21′1″ с.ш. 131°16′6″ в.д., на глубине 216−224 м при придонной температуре 1.0°С. На нерестилище обнаружены производители и яйцевые капсулы.

Особенности распределения промысловых скоплений сайры в северо-западной части Тихого океана по данным поисково-промысловых работ в

Finding of female pelagic skate stingray Pteroplatytrygon violacea with a length of TL 996 mm in Russian waters off the South Kuril region is reported. Description is provided and data on occurrence of this species in this region are generalized.

Main features of spatial distribution and thermal regime of habitation of Lycodes nakamurae and L. yamatoi in Russian waters of the Sea of Japan are discussed. Comparative analysis of specific features of distribution of eelpouts of the mesobenthal group (L. nakamurae, L. yamatoi, L. tanakae) in some areas of the Sea of Japan with different hydrological conditions is provided. No horizontal migrations directed along isobaths were revealed in these species. In Russian waters of the Sea of Japan, L. nakamurae inhabits depths 130–760 m, preferring the range of depths 200–700 m (it was found in catches of 95.7% of trawlings); L. yamatai inhabits depths 140–800 m, but most frequently is found in the range of depths 200–500 m (86.1% of trawlings). L. nakamurae occurs at a temperature of 0.4–1.2°C and L. yamatoi is found at 0.3–1.9°C. Seasonal migrational activity in the former species is more pronounced than in the latter. Spring-summer migration towards the shelf for feeding and reproduction and autumn-winter wintering migration towards the continental slope taking place with the cooling of the shelf are noticeable. Maximum range of vertical migrations is typical of medium-size fish and minimal is typical of juveniles of the studied species that inhabit the upper section of the bathyal (200–400 m). It is suggested that the lower limit of distribution of eelpouts of the mesobenthal group in the southern and northern sectors of the Sea of Japan coincide. The upper boundary of habitation of the species in different seasons of the year is totally determined by the thermal regime of water masses in different areas of the sea.

Обсуждаются основные черты пространственного распределения и термического режима обитания Lycodes nakamurae и L. yamatoi в российских водах Японского моря. Приводится сравнительный анализ особенностей распределения ликодов мезобентальной группировки (L. nakamurae, L. yamatoi, L. tanakae) в некоторых районах Японского моря с разными гидрологическими условиями. Горизонтальные миграции, направленные вдоль изобат, у данных видов не выявлены. В российских водах Японского моря L. nakamurae обитает на глубинах 130–760 м, предпочитая диапазон глубин 200–700 м (обнаружен в уловах 95.7% тралений); L. yamatoi обитает на глубинах 140–800 м, но наиболее часто встречается в диапазоне глубин 200–500 м (86.1% тралений). L. nakamurae встречается при температуре 0.4–1.2°С, L. yamatoi – при 0.3–1.9°С. Сезонная миграционная активность у первого вида более выражена, чем у второго. Заметны весенне-летнее перемещение рыб в сторону шельфа для нагула и размножения и осенне-зимняя зимовальная миграция в сторону материкового склона, происходящая по мере выхолаживания шельфа. Наибольший диапазон вертикальных миграций свойствен среднеразмерным рыбам, наименьший – молоди исследованных видов, которая обитает в верхнем отделе батиали (200–400 м). Предполагается, что нижний предел распространения ликодов мезобентальной группировки в южном и северном секторах Японского моря совпадает. Верхняя граница обитания видов в разные сезоны года целиком определяется термическим режимом водных масс в разных районах моря.

Based on materials of bottom inventory trawl survey performed in summer 2008 in the western part of the Bering Sea, we show that representatives of the genus Lycodes in the summer period occur almost throughout the study water area of the sea from the sublittoral to the drop-off. The pattern of distribution and abundance of particular species depend on the depth and specific features of the hydrological regime of the given area. The most numerous species— Lycodes brevipes and L. palearis —are found in warm intermediate and in cold demersal water masses, are distributed over a vast stretch, and there form considerable concentrations. Deep-water species— L. beringi and L. concolor —are more stenothermal, occur along the narrow band of the continental slope, and are considerably inferior to stretch species in numbers. Of shallow species dwelling at depths smaller than 100 m, only L. raridens has high numbers and occurs over a considerable area in the northern part of the study area, the remaining species ( L. mucosus, L. polaris , and L. turneri ) are caught in small amounts at local sites. The largest sizes are in L. raridens and L. concolor , their maximum length in catches is more than 70 cm, the former species reaches maximum length in the seventh year of life, and the latter reaches maximum length in the ninth year. The smallest and slowest-growing among the studied fish is L. brevipes : its maximum length in catches does not exceed 39 cm and maximum age is 7 years.

According to data of long-term observations in Russian waters of the Sea of Japan, it was shown that skate Raja pulchra occurs only off the coasts of western Sakhalin. In all probability, it is a constant inhabitant of these waters during the course of the year; like the overwhelming majority of bottom and near-bottom fish, it performs seasonal bathymetric migrations in autumn, for wintering to the insular slope to a depth of 695 m, and in spring to shallow waters. Maximum length of R. pulchra recorded in catches is 106 cm. The main food items of R. pulchra are decapods and fish. The stock of R. pulchra off the coasts of western Sakhalin is assessed as 520 t.

It has been found, with reference to the data of trawl survey and literature, that, in the Sea of Japan, the Northern boundary of the area of the elongated sculpin Alcichthys elongatus is the central part of the Tatar Strait. During the year, the elongated sculpin occurs at depths from 7 to 650 m. Its highest concentration forms during the feeding period. At this time Alcichthys elongatus stays up to depths 253 m but prefers the range of 40–100 m. It winters below the 50 m isobath, mainly in the lower part of the shelf and in the upper section of the continental slope. Being an eurythermal species, the elongated sculpin occurs in a wide range of temperature (from −1.6 to 17.7°C). However, most specimens prefer waters with slightly positive temperature. Juveniles prefer the warm water layers. Males are larger than females but the latter dominate in catches. According to the kind of diet A. elongatus, it is a benthoichtyophage consuming predominantly decapods (mostly juveniles of Chionoecetes opilio) and small fish. In summer, the value of daily ration is 3.0% of the body weight. In the north-western part of the Sea of Japan, A. elongatus may be characterized as a common species with a low but stable abundance.

Juveniles of Leptoclinus maculatus diaphanocarus were observed in great numbers in netting of bottom trawl in the period from April 28 to May 7 2007 in the Tatar Strait. Metamorphosis of juveniles reached its end at the body length from 8.5 to 11.0 cm. It was accompanied by change of coloration. After transition to the bottom mode of life, the frequency of occurrence of specimens of this species in catches drastically decreased. Principal counts are estimated, with consideration of additional material from far eastern seas of Russia. Two groups of specimens which would correspond to the Pacific and the Atlantic subspecies sensu Andriashev are not found. It is suggested that, for determination of the actual taxonomic status of intraspecies groups of the species L. maculatus, additional comparative material on morphology and genetics is needed from different regions.

С целью определения положения в системе подотряда Zoarcoidei проведено молекулярно-генетическое и сравнительно-морфологическое изучение представителя криворотовых рыб семейства Cryptacanthodidae – криворота Берга Cryptacanthodes bergi из зал. Петра Великого (Японское море). Молекулярно-генетический анализ с использованием генов митохондриальной и ядерной ДНК показал существенное сходство криворота Берга с представителями надсемейства Stichaeoidae, что не подтвердило мнение Макушка о филогенетической обособленности криворотов от стихеевых и близких к ним семейств рыб. Обнаружены анатомические особенности в строении черепа, подтверждающие молекулярно-генетические данные. Обсуждаются пути и время проникновения криворотов в северо-западную Атлантику через пролив на месте Панамского перешейка примерно в конце миоценового периода.

To determine the taxonomic position of wrymouths of the family Cryptacanthodidae in the system of the suborder Zoarcoidei, a study on molecular genetics and comparative morphology of Cryptacanthodes bergi from Peter the Great Bay (Sea of Japan) is conducted. Based on molecular genetic analysis using the genes of nuclear and mitochondrial DNA, Cryptacanthodes bergi is substantially similar to the representatives of the superfamily Stichaeoidae. Thus, the opinion of Makushok on a phylogenetically distinct position of wrymouths in relation to snake blennies and related families is not supported. The anatomical features of skull structure support the data of molecular genetics. The directions and time of distribution of wrymouths in the northwest Atlantic through the channel in the area of the Isthmus of Panama in approximately the late Miocene are discussed.