Sea anemones (Actiniaria, Corallimorpharia and Zoantharia) from the Western Bering Sea (Northwest Pacific)

© INVERTEBRATE ZOOLOGY, 2023Invertebrate Zoology, 2023, 20(1): 27–56 Sea anemones (Actiniaria, Corallimorpharia and Zoantharia) from the Western Bering Sea (Northwest Pacific) N.P. Sanamyan1, K.E. Sanamyan1, E.S. Bocharova2, T.B. Morozov3, S.V. Galkin4 1 Kamchatka Branch of Pacific Geographical Institute, Far Eastern Branch of the Russian Academy of Sciences, Partizanskaya 6, Petropavlovsk-Kamchatsky, 683000, Russia. E-mail: [email protected] 2 Koltzov Institute of Developmental Biology of Russian Academy of Sciences, Vavilova Str. 26, Moscow, 119334, Russia. E-mail: [email protected] 3 Kamchatka Branch of the Russian Federal Research Institute of Fisheries and Oceanography, Naberezhnaya Str. 18, Petropavlovsk-Kamchatsky, 683000, Russia. E-mail: [email protected] 4 Shirshov Institute of Oceanology of Russian Academy of Sciences, Nahimovskiy Pr. 36, Moscow, 117997, Russia. E-mail: [email protected] N.P. Sanamyan ORCID 0000-0002-9987-0668 K.E. Sanamyan ORCID 0000-0002-7460-3985 E.S. Bocharova ORCID 0000-0001-9978-3006 T.B. Morozov ORCID 0000-0001-6782-6921 S.V. Galkin ORCID 0000-0002-9748-5168 ABSTRACT: The paper presents a review of the fauna of sea anemones collected and/or documented photographically in the western part of the Bering Sea: in the areas of the Vulcanologov Massif, Karaginsky and Olyutorsky Gulfs and Koryak slope. In total, about 80 species have been identified and an annotated list of sea anemones of the orders Actiniaria, Corallimorpharia, and Zoantharia is provided. This is the first comprehensive report of the species diversity of sea anemones living in the western Bering Sea, based on the recent collections and underwater imaging. How to cite this atricle: Sanamyan N.P., Sanamyan K.E., Bocharova E.S., Morozov T.B., Galkin S.V. 2023. Sea anemones (Actiniaria, Corallimorpharia and Zoantharia) from the Western Bering Sea (Northwest Pacific) // Invert. Zool. Vol.20. No.1. P.27–56, Suppl. Tables 1–2. doi: 10.15298/invertzool.20.1.02 KEY WORDS: NW Pacific, Bering Sea, sea anemones, Actiniaria, Corallimorpharia, Zoantharia, deep-sea fauna, biodiversity. Фауна морских анемон (Actiniaria, Corallimorpharia и Zoantharia) западной части Берингова моря (Северо-Западная Пацифика) Н.П. Санамян1, К.Э. Санамян1, Е.С. Бочарова2, Т.Б. Морозов3, С.В. Галкин4 1 Камчатский филиал Тихоокеанского института географии ДВО РАН, ул. Партизанская, 6, Петропавловск-Камчатский 683000, Россия. E-mail: [email protected] 2 Институт биологии развития им. Н.К. Кольцова РАН, ул. Вавилова, 26, Москва, 119334, Россия. E-mail: [email protected] 3 Камчатский филиал Всероссийского научно-исследовательского института рыбного хозяйства и океанографии, ул. Набережная, 18, Петропавловск-Камчатский 683000, Россия. 28 N.P. Sanamyan et al. E-mail: [email protected] 4 Институт океанологии им. П.П. Ширшова РАН, Нахимовский пр., 36, Москва, 117997, Россия. E-mail: [email protected] РЕЗЮМЕ: В статье представлен обзор фауны морских анемон, собранных и/или задокументированных на фотои видеоизображениях в западной части Берингова моря: в районах массива Вулканологов, Карагинского и Олюторского заливов и Корякского склона. Всего выявлено около 80 видов и приведен аннотированный список морских анемон отрядов Actiniaria, Corallimorpharia и Zoantharia. Это первое обобщение данных о видовом разнообразии морских анемон, обитающих в западной части Берингова моря, основанное на недавних коллекционных сборах и подводных фотои видеосъемках. Как цитировать эту статью: Sanamyan N.P., Sanamyan K.E., Bocharova E.S., Morozov T.B., Galkin S.V. 2023. Sea anemones (Actiniaria, Corallimorpharia and Zoantharia) from the Western Bering Sea (Northwest Pacific) // Invert. Zool. Vol.20. No.1. P.27–56, Suppl. Tables 1–2. doi: 10.15298/invertzool.20.1.02 КЛЮЧЕВЫЕ СЛОВА: Северо-Западная Пацифика, Берингово море, морские анемоны, актинии, кораллиморфарии, зоантарии, глубоководная фауна, биоразнообразие. most part of the Bering Sea: Metridium farcimen, Halcampa vegae Carlgren, 1921, Stomphia coccinea (O.F. Müller, 1776) and Urticina crassicornis (O.F. Müller, 1776) (Torrey, 1902, 1906; Carlgren, 1921, 1940; Eash-Loucks, Fautin, 2012; Larson, Daly, 2015; Larson, 2016). Only 11 species of Actiniaria are known from the shallow waters of the Commander Islands in the southwestern part of the Bering Sea: Paraisanthus tamarae Sanamyan et Sanamyan, 1998, Metridium senile fimbriatum Verrill, 1865, Stomphia coccinea, Anthopleura orientalis Averincev, 1967, Aulactinia stella (Verrill, 1864), Aulactinia sp., Cnidopus japonicus (Verrill, 1869), Cribrinopsis albopunctata Sanamyan et Sanamyan, 2006, C. olegi Sanamyan et Sanamyan, 2006, Urticina grebelnyi Sanamyan et Sanamyan, 2006 and U. timuri Sanamyan et Sanamyan, 2020 (see Sanamyan, Sanamyan, 1998, 2006, 2015, 2020). In the present work we summarize available and newly obtained data on diversity and distribution of sea anemones in the western Bering Sea. Material and methods The present work is based partly on the collected specimens, partly on the photographic images and video records taken during the following expeditions: 1) Cruise 22 of RV Akademik Mstislav Keldysh in 1990, collections were made by Sigsbee trawl, Introduction Until recent time deep-water fauna of sea anemones of Bering Sea was practically unknown with only one species, Liponema brevicorne (McMurrich, 1893) recorded at the depths greater than 100 m: one specimen of this species was reported from 1019 m in the Bowers Bank, one specimen from 580–680 m and 25 specimens from 135 m in eastern part of Bering Sea (Dunn, Bakus, 1977; Eash-Loucks, Fautin, 2012). In 2001 we described Neohalcampa sheikoi Sanamyan, 2001 from Karaginsky Island (from 240–580 m) (Sanamyan, 2001), and recently gave first preliminary data on 11 species recorded on the Vulcanologov Massif (Sanamyan, Sanamyan, 2018; Galkin et al., 2019; Krylova et al., 2019; Morduhovich et al., 2019; Rybakova et al., 2020) and described four new species from the Vulcanologov Massif and Koryak slope (Sanamyan et al., 2021). More species were known for the depths shallower than 100 m. Seven of them were reported in eastern part of the Bering Sea: Edwardsia sipunculoides (Stimpson, 1853), Peachia parasitica (Agassiz, 1861), Halcampoides purpureus (Studer, 1879), Anthopleura xanthogrammica (Brandt, 1835), Epiactis ritteri Torrey, 1902, Metridium farcimen (Brandt, 1835) and Acricoactis brachyacontis Larson, 2016. Four species are known for the northern- 29Actiniaria, Corallimorpharia and Zoantharia from the Western Bering Sea Fig. 1. Map showing western part of the Bering Sea; study area is marked by yellow; numbers 3, 4, 5 indicate transects (red lines) investigated by ROV Comanche 18 during cruise 82 of RV Akademik M.A. Lavrentyev on Koryak slope in 2018. Рис. 1. Карта районов исследований (отмечены желтым цветом) в западной части Берингова моря; цифрами 3, 4, 5 обозначены номера трансект (красные линии), выполненнх на Корякском склоне аппаратом “Команч 18” в 82-м рейсе НИС “Академик М.А. Лаврентьев” в 2018 г. During these cruises the following regions in the western part of the Bering Sea were investigated (Fig. 1): Vulcanologov Massif in the south of Komandorsky Basin (southwestern part of the Bering Sea) up to maximal depths 4277 m (Komandor Graben); Koryak slope between the Cape Olyutorsky and the Cape Navarin, Karaginsky and Olutorsky Gulfs and continental slope between the Cape Ozernoy and the Cape Olyutorsky (western part of the Bering Sea). The geomorphology of the Vulcanologov Massif is given according to Baranov et al., 2021. The list of stations where sea anemones were recorded is given in Supplement Table 1. Collected specimens were fixed in 4% buffered formalin for morphological study and small pieces cut from larger specimens were fixed in 96% ethanol and kept in refrigerator for molecular analysis. Molecular data were used to separate species of Actinosdredging and manned submersibles Mir-1 and Mir2, Shirshov Institute of Oceanology of Russian Academy of Sciences; 2) Cruise 75 of RV Akademik M.A. Lavrentyev in 2016, ROV Comanche 18, A.V. Zhirmunsky National Scientific Center of Marine Biology, Far East Branch of Russian Academy of Sciences (NSCMB FEB RAS); 3) Cruise 82 of RV Akademik M.A. Lavrentyev in 2018, ROV Comanche 18, NSCMB FEB RAS; 4) Cruise 99 of RV Professor Levanidov in July– August 2019, bottom trawl, Kamchatka Branch of the Russian Federal Research Institute of Fisheries and Oceanography (KamchatNIRO); 5) Cruise 37 of RV Professor Kaganovsky in 2020, bottom trawl, KamchatNIRO; 6) FV (Fishing freezer trawler) Valeriy Maslakov in 2021, bottom trawl, KamchatNIRO. 30 N.P. Sanamyan et al. tolidae and Sicyonidae. Total DNA was extracted using Wizard SV Genomic DNA Purification System (Promega) following the manufacturer’s protocol. The mitochondrial (12S rRNA, 16S rRNA, COIII) and nuclear (18S rRNA and 28S rRNA) gene fragments were amplified using published primers and protocols (Geller, Walton, 2001; Bocharova, 2015; Sanamyan et al., 2018). Photo and video surveys were carried out in situ during the 75th cruise of the RV Akademik M.A. Lavrentyev (June–July 2016) on the northern slope of the Vulcanologov Massif and during the 82th cruise of the RV Akademik M.A. Lavrentyev (June– July 2018) on the southern slope of the Vulcanologov Massif and on the northern and southern tops of the Piip Volcano in the southwestern part of the Bering Sea and on the Koryak slope in the western part of the Bering Sea. In addition, in these cruises and cruises of the RV Professor Levanidov (cruise code 201999) in 2019, RV Professor Kaganovsky (cruise 37) in 2020 and FFT Valeriy Maslakov in 2021, freshly collected specimens were photographed live on board. All photographs (except Figs 3H, 5B) were taken using ROV Comanche 18 cameras, NSCMB FEB RAS. Systematic Account Order Actiniaria Family Relicanthidae Rodríguez et Daly, 2014 Relicanthus cf. daphneae (Daly, 2006) Fig. 2A. Boloceroides daphneae Daly, 2006: 1241; Desbruyeres, Segonzac, Bright, 2006: 72. Relicanthus daphneae: Rodríguez et al., 2014: 7; Xiao et al., 2019: 1. MATERIAL. LV-82-5, 55.2700ºN 167.2991ºE – 55.2738ºN 167.2974ºE, depth 3494–3435 m, one specimen photographed; LV-82-6, 55.6972ºN 167. 1262ºE, depth 3948 m, one specimen photographed. REMARKS. Relicanthus daphneae is a large characteristically looking rose-colored sea anemone with very long tentacles tapering to thin threads (estimated to be up to 40 cm in length). One specimen was photographed attached on the stalk of a glass sponge Hyalonema, covered with a colony of zoantharian Epizoanthus fatuus (on the southern slope of the Vulcanologov Massif), another appeared sitting directly on the bottom (in the small high in Komandorsky Basin). This very interesting species was reported for the first time in the Bering Sea and the current record is most northern and most deep-water one for this species (3435–3948 m). Previous records were from 13ºN to 23ºS on the East Pacific Rise, 32ºS Pacific Antarctic Ridge on the depths 2235–2650 m (Daly, 2006; Desbruyeres et al., 2006) and from 27.25ºS South East Indian Ridge in Indian Ocean on the depth 3005 m (Gerdes et al., 2021). Taxonomic position of this species is not clear (see Rodríguez et al., 2014; Xiao et al., 2019). Family Actinernidae Stephenson, 1922 Actinernus robustus (Hertwig, 1882) Fig. 2B. Porponia robusta Hertwig, 1882: 113; Carlgren, 1914: 54; 1949: 21. Actinernus robustus: Uchida, 2007: 20 (and synonymy). MATERIAL. LV-75-22, 55.5100ºN 167.3240ºE – 55.5040ºN 167.3196ºE, depth 3561–3485 m, one specimen collected (sample 8) and ten specimens photographed. LV-82-5, 55.2696ºN 167.2994ºE, depth 3526 m, sample 5, one specimen collected; LV-82-6, 55.6946ºN 167.1238ºE – 55.6825ºN 167.1075ºE, depth 3906–3393 m, four specimens collected (sample 3) and four specimens photographed. REMARKS. Twenty specimens were photographically documented in the abyssal zone off northern and southern slopes of the Vulcanologov Massif, six of them were collected. The records of this unusual large (up to 20 cm in the diameter of the tentacular crown) anemone are very rare, in the Bering Sea it is reported for the first time. This is most northern and most deep-water (3393–3906 m) record of this species. Previously Actinernus robustus was known from Pacific coasts of Japan: originally it was described from the material collected off Japan by Challenger Expedition (3429 m, Hertwig, 1882; Carlgren, 1949) and then reported by Uchida (2007) from the same region from 1008–1200 m. Family Edwardsiidae Andres, 1881 Edwardsia spp. Fig. 2C. MATERIAL. LV-82-5, 55.2700ºN 167.2991ºE – 55.2738ºN 167.2974ºE, depth 3494–3435 m, one specimen photographed; LV-82-8, 55.3806ºN 167. 2617ºE, depth 485 m, one specimen photographed. REMARKS. Two small species, photographically documented on the southern slope of the Vulcanologov Massif and Piip Volcano, but not collected, most probably belong to the genus Edwardsia. They have a typical for this genus octomerous arrangement of the tentacles and their column is buried in the sediment. The first species is white, with 16 31Actiniaria, Corallimorpharia and Zoantharia from the Western Bering Sea Fig. 2. A — Relicanthus cf. daphneae; B — Actinernus robustus; C — Edwardsia sp.; D–E — Edwardsiidae spp. from the Vulcanologov Massif; F — Edwardsiidae sp. from the Koryak slope; G — Dactylanthus sp.; H — Cribrinopsis sp.1; I — cf. Urticina sp.; J — Liponema brevicorne; K — Sicyonis denisovi; L — S. kuznetsovi. Рис. 2. A — Relicanthus cf. daphneae; B — Actinernus robustus; C — Edwardsia sp.; D–E — Edwardsiidae spp. на массиве Вулканологов; F — Edwardsiidae sp. на Корякском склоне; G — Dactylanthus sp.; H — Cribrinopsis sp.1; I — cf. Urticina sp.; J — Liponema brevicorne; K — Sicyonis denisovi; L — S. kuznetsovi. 32 N.P. Sanamyan et al. tentacles arranged in two circles (8+8), recorded in abyssal zone at 3435–3494 m (Fig. 2C). Another species with transparent tentacles and eight white spots on the oral disc at the bases of the tentacles was photographed in the bathyal zone at 485 m on cold seeps field between bacterial mats. Edwardsiella sp. MATERIAL. LV-75-21, 55.4818ºN 167.2573ºE, 2841 m, one specimen photographed. REMARKS. Small inconspicuous sea anemone with worm-like column hidden in substrate photographically documented on the northern slope of the Vulcanologov Massif at 2841 m is identified as a member of the genus Edwardsiella (subfamily Edwardsiellinae, see Sanamyan, Sanamyan, 2021 for this subfamily name). Its rather long tapering scapulus and upper part of the scapus, covered by periderm, project from substrate and are well visible. Members of this genus live in crevices in rock, between the stones and other hard substrates, are difficult to collect and therefore the records are few. In the North Pacific Edwardsiella was recorded only once: a shallow water species of this genus was recently recorded in British Columbia (Sanamyan et al., 2018). Edwardsiidae spp. Fig. 2D–F. MATERIAL. AMK-22-2321, 55.3716°N 167. 3133°E – 55.3633°N 167.3°E, depth 1490–1554 m, dredge, 25 specimens collected. LV-75-17, 55.4527ºN 167.2653ºE, depth 2044 m, one specimen photographed; 55.4454ºN 167. 2627ºE, depth 1851 m, one specimen photographed. LV-75-21, 55.4839ºN 167.2582ºE, depth 2878 m, one specimen photographed; 55.4770ºN 167.2518ºE – 55.4733ºN 167.2527ºE, depth 2704–2636 m, eight specimens photographed. LV-82-9, 55.3466ºN 167.2752ºE – 55.3550ºN 167.2726ºE, depth 1933–1611 m, four specimens photographed. LV-82-12, 60.8671ºN 174.3183ºE – 60.8723ºN 174.3104ºE, depth 506–489 m, two specimens photographed; LV-82-13, 60.8298ºN 174. 3769ºE – 60.8388ºN 174.3689ºE, depth 677–611 m, seven specimens photographed; LV-82-14, 61. 0958ºN 175.0119ºE – 61.1202ºN 174.9662ºE, depth 884–660 m, 23 specimens photographed; LV-8215, 61.1430ºN 174.9285ºE – 61.1779ºN 174.8708ºE, depth 517–417 m, 68 specimens photographed; LV82-16, 61.1787ºN 174.8704ºE – 61.1899ºN 174. 8345ºE, depth 415–356 m, about 1160 specimens photographed; LV-82-17, 61.1806ºN 174. 8508ºE – 61.1801ºN 174.8493ºE, depth 402–400 m, 25 specimens photographed; LV-82-18, 61.1198ºN 174. 9638ºE – 61.1197ºN 174.9652ºE, depth 652–663 m, eight specimens photographed; LV-82-19, 61. 1539ºN 175.4492ºE – 61.1538ºN 175.4493ºE, depth 693 m, 16 specimens photographed; LV-82-20, 61. 1713ºN 174.8810ºE – 61.1727ºN 174.8781ºE, depth 430–427 m, 23 specimens photographed; LV-8221, 60.8305ºN 174.3770ºE – 60.8343ºN 174. 3720ºE, depth 672–660 m, five specimens photographed. REMARKS. At least five other species of Edwardsiidae may be recognized in the photo and video files taken by ROV Comanche 18. Four of them were photographed but not collected on the Vulcanologov Massif. All four species are present on the northern slope of the Vulcanologov Massif and one of them is recorded also on the southern slope of the Piip Volcano. The latter species, photographed at 1611–1933 m, lives in mud, has pale-rose coloration, small oral disc and rather long not numerous (about 10) tentacles. Remaining three species were recorded deeper than 2000 m: two of them live in mud, both are white, one has up to 16 short tentacles, another about 30 long tentacles (Fig. 2D), and one species inhabits shallow crevices on the stones (Fig. 2E). The latter species has cylindrical column, scapus covered by periderm, short white scapulus and about 26 thin white tentacles. Another species of Edwardsiidae was recorded on the Koryak slope at 356–884 m (Fig. 2F). The specimens are numerous (more than 1330 specimens seen on the photographs but not collected), live on muddy bottom. This species has about 16 thin long tentacles, tentacular crown up to 4 cm in diameter. Oral disc has eight dark spots arranged in a circle. The body is up to 5 mm in diameter, scapulus transparent with white strokes in upper part and dark-red rim. This species recorded in the background community around cold seep fields which included the sea pen Halipteris cf. willemoesi (Kölliker, 1880) with the commensal ophiuroid Asteronyx and the echinoid Brisaster latifrons (Agassiz, 1898), and also in proximity of bacterial mats at cold seeps (Krylova et al., 2018), but not recorded directly on the seeps and bacterial mats. However, most dense populations of these Edwardsiidae, up to 100 specimens per m2, was recorded during the dive 16 (station LV-82-16) at 356–415 m in the settlement of dominated here sea anemone Sagartiogeton californicus, where cold seeps have not been found. Family Preactiniidae England in England et Robson, 1984 Dactylanthus sp. Fig. 2G. MATERIAL. LV-82-10, 55.2882ºN 167.3011ºE – 55.2898ºN 167.2974ºE, depth 2778–2638 m, one specimen photographed. 33Actiniaria, Corallimorpharia and Zoantharia from the Western Bering Sea REMARKS. This is probably the most interesting record of sea anemone made on the Vulcanologov Massif during recent cruises in the Bering Sea. One large specimen was recorded attached to a vertical rock wall on the southern slope of the Piip Volcano at the depth of about 2700 m. Unfortunately, the ROV failed to collect this specimen, but it was possible to took very detailed photographs. The specimen has long (about 30 cm) cylindrical column covered by small sparse tentacle-like papillae and 24 short tentacles arranged in three cycles (6+6+12) at the margin of the oral disc. The body wall is thin and transparent, all internal structures are clearly visible through it. The shape and structure are so unusual and so closely resemble Dactylanthus antarcticus (Clubb, 1908), that we have no doubt that this species belongs or is closely related to the genus Dactylanthus (see Sanamyan et al., 2015b for photographs of live specimens of D. antarcticus from Antarctic). Previously this monotypic genus was known only in the Antarctic at the depth 20–610 m (Dunn, 1983; Sanamyan et al., 2015b). For a long time, this genus, together with related Preactis (monotypic) and Ptychodactis (two species), was treated as a member of a separate order Ptychodactiaria Carlgren, 1940, but then assigned to the order Actiniaria basing on molecular data. The specimen from the Bering Sea cannot be conspecific with Antarctic D. antarcticus due to geographical and depth separation and is most probably represents the second, undescribed species of this genus. Family Ptychodactinidae Appellöf, 1893 Ptychodactis patula Appellöf, 1893 Ptychodactis patula Appellöf, 1893: 4; Carlgren, 1911: 12; 1921: 11; 1934: 348; 1940: 19; 1049: 11; Stephenson, 1922: 249; Cappola, Fautin, 2000: 995; Grebelny, 2007: 59. MATERIAL. PL-99-6, 58.443ºN 162.823ºE – 58.468ºN 162.838ºE, depth 58–55 m, one specimen collected. REMARKS. This arctic-boreal species is known from the depths 47–350 m (Carlgren, 1949; Grebelny, 2007). In the Bering Sea it was reported only in most northern part, in the Bering Strait (Grebelny, 2007). For western part of the Bering Sea it is reported for the first time. Family Actiniidae Rafinesque, 1815 Cribrinopsis sp. 1 Fig. 2H. MATERIAL. LV-82-7, 55.3689ºN 167.2659ºE– 55.3732ºN 167.2656ºE, depth 984–815 m, one specimen collected (sample 1) and four specimens photographed; LV-82-8, 55.3765ºN 167.2639ºE, depth 670 m, one specimen photographed. LV-82-11, 60. 8544ºN 174.3484ºE, depth 553 m, one specimen photographed; LV-82-13, 60.8322ºN 174.3754ºE – 60.8336ºN 174.3734ºE, depth 677–609 m, two specimens photographed; LV-82-15, 61.1399ºN 174. 9333ºE – 61.1523ºN 174.9126ºE, depth 535–489 m, one specimen collected (sample 6) and five specimens photographed; LV-82-18, 61.1193ºN 174. 9692ºE – 61.1195ºN 174.9650ºE, depth 677–658 m, one specimen collected (sample 3) and three specimens photographed; LV-82-21, 60.8305ºN 174. 3770ºE – 60.8343ºN 174.3720ºE, depth 672–660 m, one specimen photographed. REMARKS. 20 specimens are photographically documented (six of them on the Piip Volcano and 14 on the Koryak slope) at depths of 489–984 m, three of which were collected. All specimens were solitary, at a large distance from each other, not in groups. Most specimens are decamerous, with up to 80 tentacles arranged in four cycles (10+10+ 20+40=80). Only one specimen was octomerous with the tentacles distributed as 8+8+16(?)+ 32(?)=64(?) (only 58 of which are visible in the photo; possibly this is young specimen which yet not acquired decamerous arrangement, see Sanamyan et al., 2019 for discussion of the details of acquiring a decamerous arrangement). All specimens have a plain bright-rose color. The upper part of the column projects above the surface of the soft bottom, the margin with the spherules bent in the horizontal direction, the number of marginal spherules (one in each endoand exocoel) corresponds to the number of tentacles. The actinopharynx is bright rose-red. Thin red lines mark insertions of the mesenteries on the oral disc, sometimes thin white radial lines are visible near the bases of the tentacles. The tentacles are long (inner ones as long as the diameter of the oral disc), sharply pointed, with moiré. The diameter of the expanded tentacular crown is up to 20 cm, the diameter of the column is up to 10 cm. Many red shrimps are present around. The species was found on the southern slope of the Piip Volcano at depths of 670–984 m, and on the Koryak slope at depths of 489–677 m. The species was also present near bacterial spots and near the cold seeps with the symbiotrophic bivalve Calyptogena pacifica Dall, 1891 (see Krylova et al., 2018). Cribrinopsis spp. MATERIAL. PL-99-83, 60.480°N 171.747°E – 60.485°N 171.758°E, depth 102 m, sample 16, one specimen collected; PL-99-92, 60.700°N 172.473°E – 60.693°N 172.447°E, depth 99–98 m, sample 19, one specimen collected. PK-37-5, 59.193°N 166.372°E – 59.186°N 166. 347°E, depth 540 m, sample 3, one specimen collect- 34 N.P. Sanamyan et al. ed; PK-37-6, 59.202°N 166.354°E – 59.191°N 166. 334°E, depth 443–445 m, sample 2, one specimen collected; PK-37-52, 61.347°N 175.551°E – 61. 338°N 175.528°E, depth 245–250 m, sample 20, one specimen collected. VM-119, 60.8533ºN 172.9166ºE – 60.8433ºN 172.8766ºE, depth 132–130 m, sample 6, one specimen collected. REMARKS. The specimens of Cribrinopsis without marginal spherules are probably represented by at least two species. They were recorded at depths of 98–540 m on the shelf and continental slope of the western part of the Bering Sea. Urticina timuri Sanamyan et Sanamyan, 2020 Urticina timuri Sanamyan, Sanamyan, 2020: 74. Urticina crassicornis: Sanamyan, Sanamyan, 2006: 379; 2009: 169; 2010: 220. Urticina felina crassicornis: Carlgren, 1921: 172, for Bering Island only. Not Actinia crassicornis O.F. Müller, 1776: 231. MATERIAL. PL-99-15, 59.223°N 163.530°E – 59.240°N 163.530°E, depth 27 m, sample 2, one specimen collected. REMARKS. This species has absolutely smooth column. Carlgren (1921: 172) reported it (as Urticina felina crassicornis) from the Bering Sea near the Bering Island from the depths 118–136 m and this is most deep-water record for this species. Thus in vicinity of Bering Island this species occurs from intertidal zone to at least 136 m. The species was recorded for the first time for Karaginsky Gulf. Urticina sp. MATERIAL. PL-99-83, 60.480°N 171.747°E – 60.485°N 171.758°E, depth 102 m, sample 17, one specimen collected. REMARKS. The species has smooth body; it differs from Urticina timuri in the size of its nematocysts. cf. Urticina sp. Fig. 2 I. MATERIAL. LV-82-11, 60.8282ºN 174. 2954ºE – 60.8411ºN 174.3782ºE, depth 682–617 m, two specimens photographed; LV-82-15, 61.1519ºN 174.9132ºE – 61.1725ºN 174.8792ºE, depth 491– 429 m, four specimens photographed; LV-82-18, 61.1190ºN 174.9691ºE, depth 682 m, one specimen photographed. REMARKS. Seven specimens are photographically documented on the Koryak slope at depths of 429–682 m, none collected. They seem to be related to Cribrinopsis sp.1, together with which they may occur, and have the same decamerous arrangement of the tentacles in four cycles (10+10+20+40=80). However, they are paler, the oral disc is pinkishorange; tentacles are pale, transparent, thick, with blunt tips, their length is equal to the radius of the oral disc, without moiré, tips are beige-yellowish; the actinopharynx is pale. The diameter of the expanded tentacular crown is up to 10–13 cm. They are deeper buried in mud, up to the level of margin. It was not possible to determine whether they have marginal spherules. It is possible that they belong to another species of Cribrinopsis or may belong to a related genus Urticina. This species, unlike Cribrinopsis sp.1, more often occurs in community which includes the coral Halipteris cf. willemoesi with the commensal ophiuroid Asteronyx and the echinoid Brisaster latifrons. Bolocera sp. MATERIAL. AMK-22-2316, 55.6013°N 167. 384°E – 55.5833°N 167.4076°E, Sigsbee trawl, depth 4294–4200 m, two specimens collected. REMARKS. Only three specimens of this genus were known from Northwest Pacific. They were reported by Wassilieff (1908) from the Sea of Japan from 510–800 m and with some hesitation assigned to Bolocera tuediae (see Carlgren, 1949). Two other species are known from Northeast Pacific: B. pannosa McMurrich, 1893 reported off California from 757 m, and B. kensmithi Eash-Loucks et Fautin, 2012, described from 1804–4100 m from Northeast Pacific Ocean, both known from original descriptions only. Our specimens appear to be distinct from known species of Bolocera. Family Liponematidae Hertwig, 1882 Liponema brevicorne (McMurrich, 1893) Fig. 2 J. Bolocera brevicornis McMurrich, 1893: 158; 1898: 231; 1904: 257; Verrill, 1922:117. Bolocera multicornis: Carlgren, 1921: 144 (only specimens from Bering Island). Liponema multicornis: Carlgren, 1932: 260; 1933: 11 (only specimens from Bering Island). Liponema brevicornis: Carlgren, 1949: 55; Dunn, Bakus, 1977: 78. Liponema brevicorne: Eash-Loucks, Fautin, 2012: 40. MATERIAL. LV-75-2, 55.4172ºN 167.2768ºE – 55.4174ºN 167.2767ºE, depth 373–375 m, one specimen photographed; LV-75-21, 55.4875ºN 167. 2600ºE – 55.4839ºN 167.2582ºE, depth 2810– 2757 m, one specimen photographed. LV-82-9, 55.3520°N 167.2740ºE – 55.3540°N 167.2730ºE, depth 1755–1698 m, two specimens photographed; LV-82-11, 60.8224ºN 174.4023ºE – 35Actiniaria, Corallimorpharia and Zoantharia from the Western Bering Sea 60.8544ºN 174.3484ºE, depth 715–553 m, four specimens photographed; LV-82-12, 60.8550ºN 174. 3487ºE – 60.8901ºN 174.2908ºE, depth 551–431 m, eleven specimens photographed; LV-82-14, 61. 0991ºN 175.0057ºE – 61.1201ºN 174.9661ºE, depth 847–663 m, two specimens photographed; LV-8215, 61.1369ºN 174.9397ºE – 61.1733ºN 174.8775ºE, depth 547–427 m, four specimens photographed; LV-82-19, 61.1538ºN 175.4497ºE – 61.1579ºN 175. 4070ºE, depth 694–685 m, three specimens collected (sample 6) and eight specimens photographed; LV-82-21, 60.8341ºN 174.3724ºE – 60.8332ºN 174. 3740ºE, depth 660 m, one specimen photographed. REMARKS. 37 specimens of this species were photographically documented during two expeditions at the depths 373–2810 m, three of them were collected. This is a large species which usually lies unattached on soft bottom but sometimes occurs on stony bottom. The living specimens are up to 15 cm in diameter, dome-shaped, column hidden below the oral disc covered by tentacles. For movement, it can take a cylindrical shape and roll on the sea bottom (Dunn, Bakus, 1977, fig. 8). The color varies from white or pale-rose to bright-rose or purple. In the process of collecting and fixation, the tentacles fall off due to the contraction of the sphincter muscle located at the base of each tentacle, and most preserved specimens are devoid of the tentacles (partially or completely). The present species strongly resembles Liponema multicorne (Verrill, 1880), known from North Atlantic, but currently Pacific L. brevicorne and Atlantic L. multicorne are treated as valid. Thus, the specimens from the Bering Island (135 m), identified by Carlgren (1921) as Bolocera multicornis Verrill, 1880, are treated here as L. brevicorne. Third species, Liponema multiporum Hertwig, 1882, is known from South Pacific. In the western part of the Bering Sea this species was not previously reported, although it is known off the American and Asian coasts of the North Pacific from depths of 102–4134 m (Eash-Loucks, Fautin, 2012). Family Sicyonidae Hertwig, 1882 Sicyonis denisovi N. Sanamyan, K. Sanamyan, Galkin, Ivin et Bocharova, 2021 Fig. 2K. Sicyonis denisovi Sanamyan et al., 2021: 391. MATERIAL. LV-75-1, 55.4246ºN 167.2903ºE, depth 1061 m, sample 1, one specimen collected; LV-75-9, 55.4286ºN 167.2775ºE – 55.4225ºN 167. 2760ºE, depth 1000–720 m, one specimen collected (sample 2) and three specimens photographed; LV75-17, 55.4661ºN 167.2761ºE – 55.4447ºN 167. 2626ºE, depth 2488–1835 m, six specimens photographed; LV-75-18, 55.4292ºN 167.2697ºE – 55. 4290ºN 167.2706ºE, depth 1040–1030 m, three specimens photographed; LV-75-21, 55.4818ºN 167. 2573ºE – 55.4633ºN 167.2547ºE, depth 2841– 2294 m, four specimens photographed. LV-82-1, 55.4171ºN, 167.2773ºE, 386 m, sample 1, one specimen collected; LV-82-7, 55.3689ºN 167.2659ºE – 55.3740ºN 167.2653ºE, depth 1010– 785 m, two specimens collected (sample 1) and twelve specimens photographed; LV-82-8, 55. 3750ºN 167.2643ºE – 55.3795ºN 167.2620ºE, depth 755–539 m, four specimens photographed. REMARKS. 37 specimens of this species were photographically documented during two expeditions in 2016 and 2018 at the depths 386–2841 m on the top of the Piip Volcano and its southern slope, five of them were collected. This large (up to 20– 25 cm in diameter of the tentacular crown) sea anemone lives on the stones. The color is usually plain, from orange to yellow-brown or reddish-brown, the oral disc may be brighter or darker than the column. The tentacles are numerous, up to 200 or more, arranged up to five cycles. This species does not form large settlements, and specimens often occur solitarily on large distance one from another, but on these depths S. denisovi appears to be the most common species of large sea anemones in the southwestern part of the Bering Sea. It was recorded on the stones surrounded by bacterial mats in the vicinity of cold seeps and also in communities of glass sponge Farrea spp. at the depths 1750–720 m (see Rybakova et al., 2020). In the original description (Sanamyan et al., 2021) depth range is given only for collected specimens (386–1061 m). Here we report deeper records of this species (1835–2841 m) on the basis of underwater photographs on which this species may be recognized. Sicyonis kuznetsovi N. Sanamyan, K. Sanamyan, Galkin, Ivin et Bocharova, 2021 Fig. 2 L. Sicyonis kuznetsovi Sanamyan et al., 2021: 400. MATERIAL. LV-75-17, 55.4553ºN 167. 2668ºE – 55.4498ºN 167.2651ºE, depth 2131– 1976 m, one specimen collected (sample 4) and one specimen photographed. REMARKS. This large (about 18–20 cm in diameter of expanded tentacular crown) sea anemone resembles Sicyonis denisovi but may be distinguished by plain light rose-beige color and by presence of only about 80 tentacles arranged in three or four cycles in specimens of similar size (in S. denisovi they are two times more numerous). Only two specimens were photographically documented (one of which was collected) on the northern slope of the 42 N.P. Sanamyan et al. Fig. 4. A — Halcampidae sp. from the northern slope of the Piip Volcano; B — Halcampidae sp. from the Komandor Graben; C — cf. Halcampoides sp.; D — Amphianthus sp. from the northern slope of the Piip Volcano; E — Amphianthus sp. from the southern slope of the Piip Volcano; F — Paracalliactis cf. involvens; G — Hormathia sp.; H — Phelliactis sp. from the northern slope of the Piip Volcano; I — Phelliactis sp. from the southern slope of the Piip Volcano; J — aff. Hormathiidae sp. 1; K — aff. Hormathiidae sp. 2; L — Sagartiogeton californicus. Рис. 4. A — Halcampidae sp. на северном склоне вулкана Пийпа; B — Halcampidae sp. в грабене Командор; C — cf. Halcampoides sp.; D — Amphianthus sp. на северном склоне вулкана Пийпа; E — Amphianthus sp. на южном склоне вулкана Пийпа; F — Paracalliactis cf. involvens; G — Hormathia sp.; H — Phelliactis sp. на северном склоне вулкана Пийпа; I — Phelliactis sp. на южном склоне вулкана Пийпа; J — aff. Hormathiidae sp. 1; K — aff. Hormathiidae sp. 2; L — Sagartiogeton californicus. 43Actiniaria, Corallimorpharia and Zoantharia from the Western Bering Sea Family Amphianthidae Hertwig, 1882 Amphianthus spp. Fig. 4D, E. MATERIAL. AMK-22-2308, 55.412°N 167. 2345ºE, depth 1200 m, submarine Mir-2, dive 5/46, six specimens collected. LV-75-17, 55.4666°N 167.2754ºE, depth 2486 m, sample 1, several specimens collected; LV75-21, 55.4733°N 167.2527ºE – 55.4633°N 167. 2547ºE, depth 2645–2509 m, several tens specimens photographed. LV-82-7, 55.3729°N 167.2655ºE, depth 830 m, several specimens photographed. REMARKS. Small sea anemones attached to the branches of gorgonian corals. The genus Amphianthus contains 24 species, most of which come from deep water. However, only four species of this genus are known in Pacific Ocean, and all are based on few records. The specimens photographed by ROV in 2016 on the northern slope of the Vulcanologov Massif (some of which were collected) at 2486– 2645 m have almost white or pale-rose coloration of the same color as the gorgonarians to which they are attached (Fig. 4D). The specimens photographed in 2018 on the southern slope of the Piip Volcano at a shallower depth of 830 m are of saturate rose color and probably belong to another species (Fig. 4E). Family Hormathiidae Carlgren, 1932 (1889) Actinauge cf. verrillii McMurrich, 1893 Actinauge verrillii McMurrich, 1893: 184; EashLoucks, Fautin, 2012: 34. MATERIAL. PK-37-55, 61.404°N 176.353ºE – 61.397°N 176.328ºE, depth 440–430 m, sample 23, one specimen collected. REMARKS. One specimen was collected on the Koryak slope at 430–440 m. Species of Actinauge have cylindrical column covered by tubercles and resemble the species of the genus Hormathia, but members of Actinauge occur more often on soft bottom, while Hormathia prefers hard substratum. Aboral thickenings on the tentacles are present in Actinauge but not in Hormathia. Actinauge verrillii was originally described from the eastern Pacific: Galapagos Islands, the coasts of Chile and California (McMurrich 1893); later it was recorded from the Southwest Pacific (Dunn 1983) and the Northeast Pacific to the Gulf of Alaska at depths 119–4250 m (Eash-Loucks, Fautin, 2012). Our record extends known range of distribution of this species to Northwest Pacific and Bering Sea and is most northern record of this species. However, very wide geographic and bathymetric distribution sometimes may suggest that not all records were identified correctly and more than one species are involved. Paracalliactis cf. involvens (McMurrich, 1893) Fig. 4F. Adamsia involvens McMurrich, 1893: 182. Paracalliactis involvens: Carlgren, 1947: 15; 1949: 95. MATERIAL. LV-82-10, 55.2902°N 167. 3009ºE – 55.2898°N 167.2974ºE, depth 2755– 2638 m, one specimen collected (sample 3) and seven specimens photographed. REMARKS. This species is an obligate symbiont that lives on the shell of gastropods inhabited by hermit crabs. It can reach 10 cm in length in extended state. Its pedal disc covers the whole shell and capable to form carcinoecium. The column and the margin are smooth, the scapus is covered with a thin cuticle, sometimes with a layer of mud. The scapulus, the limbus and the tentacles are roseorange. Underwater photos and videos on the southern slope of the Vulcanologov Massif recorded 10 specimens, one of which was collected. Daly et al. (2004) synonymized Pacific P. involvens and North Atlantic P. consors (Verrill, 1882). However, P. consors has coronal tubercles covered by cuticle (Molodtsova et al., 2008), similar to those reported for syntypes of P. consors, which are probably characteristic for the Atlantic species. The known specimens from the Pacific Ocean have no such tubercles. Thus, at present, we prefer to separate the Atlantic and Pacific species and consider them as two species. Hormathia sp. Fig. 4G. MATERIAL. LV-75-2, 55.4172ºN 167.2768ºE – 55.4174ºN 167.2767ºE, depth 413–372 m, many specimens photographed; LV-75-3, 55.4163ºN 167. 2769ºE – 55.4168ºN 167.2760ºE, depth 355–389 m, many specimens photographed; LV-75-4, 55.4164ºN 167.2764ºE – 55.4167ºN 167.2759ºE, depth 408– 398 m, several specimens photographed; LV-75-5, 55.4166ºN 167.2757ºE, depth 392 m, a few specimens photographed; LV-75-7, 55.4164ºN 167. 2749ºE – 55.4166ºN 167.2757ºE, depth 402–377 m, several specimens photographed; LV-75-8, 55. 4159ºN 167.2734ºE – 55.4188ºN 167.2733ºE, depth 401–375 m, several specimens photographed; LV75-9, 55.4168ºN 167.2747ºE, depth 352 m, a few specimens photographed; LV-75-18, 55.4343°N 167.2673ºE – 55.4337°N 167.2676ºE, depth 1389– 1342 m, two specimens photographed. 44 N.P. Sanamyan et al. LV-82-1, 55.4166°N 167.2756ºE – 55.4159°N 167.2737ºE, depth 390–362 m, one specimen collected (sample 7) and six specimens photographed. REMARKS. Sea anemone with cylindrical column covered with brownish cuticle and rows of tubercles. The tubercles are larger distally. Short bare rose colored scapulus has tubercles. The oral disc and tentacles are orange. The oral disc is wider than the column, up to 10 cm in diameter. The tentacles without mesogloeal thickenings, arranged in five cycles on the periphery of the oral disc, up to 96 in number. The species was recorded on the northern top of the Piip Volcano at depths of 352– 415 m, where it is common: many specimens were photographed, one collected. Two specimens, probably belonging to this species, were photographed on the northern slope of the Piip Volcano at the bathyal depth of 1342–1389 m (not collected). Phelliactis spp. Fig. 4H, I. MATERIAL. LV-75-22, 55.5134ºN 167.3270ºE, depth 3599 m, one specimen photographed. LV-82-6, 55.6826°N 167.1075ºE – 55.6825°N 167.1075ºE, depth 3397–3393 m, sample 3, one specimen collected; LV-82-10, 55.3188°N 167. 2907ºE, depth 2605 m, one specimen photographed. REMARKS. Two species of Phelliactis have been recorded from the Vulcanologov Massif and Komandorsky Basin in the southwest of the Bering Sea. The specimens are large with a beige-brownish cylindrical column with longitudinal rows of tubercles (mesogloeal thickenings) and very wide oral disc (about 20 cm in diameter). The tentacles are on the margin of the oral disc, more than 100 in number. Two specimens photographed on the northern slope of the Vulcanologov Massif in 2016 (3599 m, not collected) and on the small high to the west of the Komandor Graben in 2018 (3397–3393 m, collected), most probably belong to one species. They have a similarly looking high column, large circular oral disc and long thin tentacles with weak thickenings at the base on the aboral side; the recorded depth is also similar (Fig. 4H). The specimen, photographed on the southern slope of the Vulcanologov Massif (2605 m), differs in very strong aboral thickenings on the tentacles, red undulating oral disc and lower and wider column (Fig. 4 I). aff. Hormathiidae sp.1 Fig. 4 J. MATERIAL. LV-75-18, 55.4343°N 167. 2673ºE, depth 1389 m, one specimen photographed; LV-75-21, 55.4818°N 167.2573ºE – 55.4772°N 167.2514ºE, depth 2841–2732 m, four specimens photographed. REMARKS. Five specimens of the small species were photographically documented on the sides of large stones on the northern slope of the Vulcanologov Massif at 1389–2841 m (not collected). The specimens have low column, wider at the base (up to 4 cm in diameter), covered by cuticle. Oral disc and tentacles are pale-rose. The oral disc is wide (up to 3 cm in diameter), with oral cone at its center. The tentacles are thin, its length is up to the diameter of the oral disc, without mesogloeal thickenings, up to 50 may be counted in photographs. aff. Hormathiidae sp.2 Fig. 4K. MATERIAL. LV-75-18, 55.4336°N 167. 2673ºE, depth 1349 m, one specimen photographed. REMARKS. White sea anemone was photographed on the northern slope of the Piip Volcano at the depth of 1349 m in 2016 in community of glass sponge Farrea spp. (see Rybakova et al., 2020). The tentacles are hexamerously arranged in six cycles: 6+6+12+24+48+96= up to 192 (120 tentacles are visible in the photograph). The length of the inner tentacles can be as large as the diameter of the oral disc. Brownish radial dashed lines from the base of the tentacles to the mouth extend on the oral disc above the endocoels. Family Sagartiidae Gosse, 1858 Sagartiogeton californicus (Carlgren, 1940) Fig. 4L. Sagartiogeton californicus: Eash-Loucks, Fautin, 2012: 43; Sanamyan et al., 2023: 3. MATERIAL. LV-75-3, 55.4158°N 167.2738ºE, depth 355 m, three specimens photographed; LV75-15, 55.3821°N 167.2614ºE, depth 452 m, two specimens photographed; LV-75-19, 55.382°N 167.2608ºE, depth 453 m, one specimen photographed. LV-82-1, 55.4171°N 167.2773ºE – 55.4160°N 167.2744ºE, depth 386–373 m, several specimens photographed; LV-82-8, 55.382°N 167.2608ºE, depth 458 m, one specimen photographed. LV-8211, 60.8528°N 174.3516ºE, depth 534 m, two specimens photographed; LV-82-12, 60.8549°N 174. 3485ºE – 60.8901°N 174.2908ºE, depth 550–432 m, three specimens collected (sample 1) and many specimens photographed; LV-82-14, 61.1188°N 174.9679ºE – 61.1351°N 174.9419ºE, depth 684– 554 m, one specimen collected (sample 1) and many specimens photographed; LV-82-15, 61.1396°N 174.9352ºE – 61.1779°N 174.8708ºE, depth 537– 417 m, several specimens collected (samples 3, 5, 45Actiniaria, Corallimorpharia and Zoantharia from the Western Bering Sea 10, 11, 12 and 13) and many specimens photographed; LV-82-16, 61.1787°N 174.8704ºE – 61.1899°N 174.8345ºE, depth 416–356 m, two specimens collected (sample 2) and many specimens photographed; LV-82-17, 61.1806°N 174.8508ºE – 61.1801°N 174.8493ºE, depth 402–401 m, two specimens collected (samples 4 and 6) and many specimens photographed; LV-82-19, 61.1538°N 175. 4492ºE – 61.1539°N 175.4492ºE, depth 692–693 m, one specimen collected (sample 2) and several specimens photographed; LV-82-20, 61.1713°N 174. 8810ºE – 61.1724°N 174.8794ºE, depth 430–428 m, one specimen collected (sample 4) and many specimens photographed. PL-99-123, 61.215°N 174.888ºE – 61.202°N 174.865ºE, depth 355–354 m, samples 24 and 25, two specimens collected. PK-37-34, 61.088°N 174.574ºE – 61.101°N 174.586ºE, depth 531–530 m, sample 15, one specimen collected; PK-37-36, 61.113°N 174.507ºE – 61.124°N 174.527ºE, depth 380–365 m, sample 16, one specimen collected. REMARKS. The species was photographically recorded, but not collected in 2016 on the southern top of the Piip Volcano, just near the hydrothermally active site at 453 m. Several similar specimens were documented on the southern and northern tops of the Piip Volcano at 355–458 m. Many specimens were recorded and some collected on the Koryak slope (at 354–693 m), especially in methane seeps sites, where they were numerous and occurred on any available firm substrate on muddy bottom: on pebbles, dead shells and on the shells of live gastropods or of bivalve mollusks Calyptogena and other objects. The specimens are not large (up to 8 cm in the height and the diameter of the tentacular crown), with a light column and dark reddish-brown tentacles. The tentacles are numerous, about 200. In the shallowwater methane seeps on the Koryak slope, they dominate in the communities at depths of 400– 402 m (see Galkin et al., 2019) and occur directly on bacterial mats. Sagartiogeton rufus Sanamyan et al., 2023 Fig. 5A. Sagartiogeton rufus Sanamyan et al., 2023: 5. MATERIAL. LV-75-3, 55.4160°N 167.2732º E – 55.4161°N 167.2739ºE, depth 382–351 m, many specimens photographed; LV-75-8, 55.4161°N 167. 2736ºE – 55.4163°N 167.2750ºE, depth 377–400 m, many specimens photographed; LV-75-9, 55.4156°N 167.2736ºE – 55.4160°N 167.2743ºE, depth 388– 350 m, many specimens photographed. LV-82-1, 55.4171°N 167.2773ºE – 55.4160°N 167.2744ºE, depth 386–373 m, several specimens collected (samples 6 and 7) and many specimens photographed. REMARKS. Numerous small (up to 2 cm in height) rose-orange specimens form crowded settlements on the northern top of the Piip Volcano, often together with zoantharians Epizoanthus sp. of similar size and color. However, the settlements of Sagartiogeton rufus are sparser than the settlements of the zoantarians. Sometimes they form settlements near the hydrothermal sites together with filamentous colonies of bacteria. This species has not been found elsewhere. Several specimens were collected. Family Metridiidae Carlgren, 1893 Metridium farcimen (Brandt, 1835) Fig. 5B. Actinia farcimen Brandt, 1835: 12. Metridium farcimen: Fautin, Hand, 2000: 1151 (and synonymy); Sanamyan, Sanamyan, 2009: 158, 2010: 211 (and synonymy). MATERIAL. VM-167, 59.5650ºN 165.2600ºE – 59.5500ºN 165.2300ºE, depth 94 m, sample 19, one specimen collected; VM-212, 58.7150ºN 162. 7633ºE – 58.7316ºN 162.7866ºE, depth 30–29 m, sample 26, one specimen collected. REMARKS. This species is widely distributed in the North Pacific. It has high smooth column (up to 1 m in height) and numerous (thousands) small tentacles which serve to catch small suspended in the water column particles; the species is planktivorous. Numerous records of this species are reported from American coasts from Bering Strait to Mexico and from subtidal waters to 2740 m (Eash-Loucks, Fautin, 2012). On the Asiatic side of Pacific, it was reported from Southeast Kamchatka, where its typical location is in the Avacha Bay (Fautin, Hand, 2000; Sanamyan, Sanamyan, 2009, 2010). According to personal observations and underwater photographs of N. Sanamyan this species is abundant in Avachinsky and Kronotsky Gulfs. Also, this species was photographed in the first technical dive by ROV in 2018 on the southern (Pacific) side of Bering Island (Commander Islands) on 30–33 m and in Chukotka in the Seniavin Strait (northern part of the Bering Sea) on the depth 6–8 m (Fig. 5B; personal communication and photo of Viktor Lyagushkin). Metridium sp. recorded by Averincev (1967) from Sea of Japan (Possjet Bay) probably belongs to this species. Metridium farcimen appears to be very abundant in some parts of the Northwest Pacific: more than 100 kg of this species was captured per trawling in three station during bottom trawl survey in the shelf of the Karaginsky subzone (Olyutorsky and Karaginsky Gulfs) in the Bering Sea in 2021 at depths of 29–94 m (personal communication of Taras Morozov). 46 N.P. Sanamyan et al. Fig. 5. A — Sagartiogeton rufus; B — Metridium farcimen from Chukotka (photo of Viktor Lyagushkin); C — Actiniaria sp.1; D — Actiniaria sp.2; E — Actiniaria sp.3; F — Actiniaria sp.4; G — Actiniaria sp.5; H — Actiniaria sp.6; I — Actiniaria sp.7; J — the white form of Corallimorphus cf. pilatus; K — the brown form of Corallimorphus cf. pilatus; L — Corallimorphidae sp. Рис. 5. A — Sagartiogeton rufus; B — Metridium farcimen, Чукотка (фото Виктора Лягушкина); C — Actiniaria sp.1; D — Actiniaria sp.2; E — Actiniaria sp.3; F — Actiniaria sp.4; G — Actiniaria sp.5; H — Actiniaria sp.6; I — Actiniaria sp.7; J — белая форма Corallimorphus cf. pilatus; K — коричневая форма Corallimorphus cf. pilatus; L — Corallimorphidae sp. 47Actiniaria, Corallimorpharia and Zoantharia from the Western Bering Sea Species not identified to family level Actiniaria sp.1 Fig. 5C. MATERIAL. LV-75-3, 55.4160°N 167. 2734ºE – 55.4161°N 167.2739ºE, depth 384–351 m, 27 specimens photographed; LV-75-9, 55.4158°N 167.2738ºE, depth 379 m, one specimen photographed. LV-82-1, 55.4163°N 167.2738ºE, depth 348 m, one specimen photographed. REMARKS. About 30 specimens of mediumsized (up to 5–7 cm in diameter of the tentacular crown) white sea anemones were detected, but not collected, among the settlements of zoantharians and Sagartiogeton rufus on the northern top of the Piip Volcano at 348–384 m. They have short column and long tapering tentacles arranged hexamerously in five cycles (6+6+12+24+48= up to 96), the oral disc is small, almost completely covered by the tentacles, the oral cone is high. The species has some superficial similarity with white Corallimorphus cf. pilatus, but differs in its tapering tentacles without acrospheres. Actiniaria sp.2 Fig. 5D. MATERIAL. LV-75-2, 55.4166ºN 167.2749ºE – 55.4171ºN 167.2771ºE, depth 403–367 m, several specimens photographed; LV-75-8, 55.4162ºN 167. 2736ºE – 55.4161ºN 167.2749ºE, depth 378–386 m, several specimens photographed; LV-75-9, 55. 4155ºN 167.2736ºE – 55.4161ºN 167.2743ºE, depth 394–349 m, several specimens photographed. LV-82-1, 55.4170°N 167.2770ºE – 55.4163°N 167.2738ºE, depth 368–347 m, one specimen collected (sample 7) and several specimens photographed; LV-82-8, 55.3765°N 167.2639ºE, depth 668 m, three specimens photographed. REMARKS. This small sea anemone (up to 2–3 cm in the height and the diameter of the tentacular crown) appears to be common on the northern top of the Piip Volcano at 347–403 m, and also photographed on the southern slope of the Piip Volcano at 668 m. It has short beige to orange-brownish column wide at the base and beige to orange transparent tentacles. White collar on the margin under the tentacles resembles a circle of pseudospherules in the extended specimens. This species detected on the vertical sides and undersides of large stones among small Sagartiidae Sagartiogeton rufus and corallimorpharians. One specimen was collected. Actiniaria sp.3 Fig. 5E. MATERIAL. LV-82-1, 55.4170ºN 167.2775ºE, depth 382 m, one specimen photographed. LV-8211, 60.8405ºN 174.3804ºE – 60.8543ºN 174.3490ºE, depth 621–551 m, sample 1, two specimens collected; LV-82-12, 60.8586ºN 174.3398ºE – 60.8635ºN 174.3266ºE, depth 538–518 m, four specimens photographed; LV-82-13, 60.8333ºN 174.3739ºE – 60. 8387ºN 174.3688ºE, depth 660–620 m, five specimens photographed; LV-82-14, 61.1203ºN 174. 9650ºE – 61.1332ºN 174.9453ºE, depth 664–565 m, three specimens photographed; LV-82-15, 61. 1500ºN 174.9179ºE – 61.1717ºN 174.8802ºE, depth 499–433 m, 25 specimens photographed; LV-8218, 61.1209ºN 174.9669ºE, depth 662 m, one specimen photographed; LV-82-21, 60.8305ºN 174. 3770ºE – 60.8313ºN 174.3771ºE, depth 679–674 m, 25 specimens photographed. REMARKS. Medium-sized burrowing sea anemone; only its upper part, a scapulus with the tentacles, is visible above the surface of bottom. The diameter of the tentacular crown is about 4 cm. The tentacles are dark, directed upward and slightly to the sides (i.e. they do not stand horizontally and do not touch the substrate). The tentacles are conical, probably 24 in number, usually lilac or reddish-brown or paler with two transverse dark bands of the same tint; the tips may be white. The scapulus is pale or white with a reddish-brown band in its upper part, composed of vertical lines between the insertions of the mesenteries. This color band may be poorly defined on some specimens. The scapus is covered with cuticle and firm layer of sand and gravel. One specimen of this species was photographically documented on the northern top of the Piip Volcano at 382 m, while on the Koryak slope it occurred rather often at 433– 679 m, where 65 specimens were photographed, two of which were collected. Actiniaria sp.4 Fig. 5F. MATERIAL. LV-75-18, 55.4420°N 167.2627ºE – 55.4341°N 167.2676ºE, depth 1733–1377 m, seven specimens photographed. REMARKS. Orange sea anemone of medium size anemone (up to 8–9 cm in the diameter of the tentacular crown), with short column and very long tentacles. The inner tentacles can be more than two times longer than the diameter of the oral disc. Usually occurs on the sides of large stones. Seven specimens were photographed (but not collected) on the northern slope of the Piip Volcano in the lower bathyal zone at 1377–1733 m. Actiniaria sp.5 Fig. 5G. MATERIAL. LV-82-5, 55.2616°N 167. 3025ºE – 55.2698°N 167.2992ºE, 3931–3547 m, one 48 N.P. Sanamyan et al. specimen collected (sample 2) and five specimens photographed; LV-82-10, 55.2879°N 167.3014ºE, depth 2807 m, two specimens photographed. REMARKS. A small abyssal sea anemone with a white translucent body, eight specimens of which were photographed and one collected on the southern slope of the Vulcanologov Massif at depths of 2807–3931 m in 2018. All specimens have a low column of similar height and width; the oral disc is slightly wider than the column. The tentacles are marginal, arranged in two cycles, up to 36 in number. White ova are visible in the tentacles and through the oral disc in half of the specimens. Actiniaria sp.6 Fig. 5H. MATERIAL. LV-82-14, 61.1326°N 174. 9450ºE – 61.1333°N 174.9453ºE, depth 570–565 m, four specimens photographed; LV-82-15, 61.1380°N 174.9382ºE – 61.1401°N 174.9347ºE, depth 550– 536 m, two specimens photographed. REMARKS. Medium sized (up to 8 cm in the height and the diameter of the tentacular crown) dark, plain brownish-violet sea anemones occurring on pebbles or another hard substrate on muddy bottom. High cylindrical column is much wider distally, the oral disk three times wider than the column. The tentacles are arranged in five cycles, conical, not longer than the radius of the oral disc. Six specimens are photographed (but not collected) on the Koryak slope in background community dominated by brittle stars Ophiophthalmus normani (Lyman, 1879) at 536–570 m. Actiniaria sp.7 Fig. 5 I. MATERIAL. LV-75-2, 55.4172ºN 167.2766ºE, depth 380 m, one specimen photographed; LV-753, 55.4165ºN 167.2759ºE, depth 390 m, seven specimens photographed. REMARKS. Eight specimens of this small (about 2–3 cm in height) species were photographed but not collected at 380–390 m on the northern top of the Piip Volcano. The specimens of this species are attached to the stones, they have high column (with wider basal half) divisible into scapus covered by yellow-brownish cuticle and white bare scapulus. Longitudinal lines, probably insertions of the mesenteries are visible on the column. Mesenteries arranged probably in three cycles. Dark tentacles are probably arranged in four cycles. The specimens of this species occur on the upper and lower surfaces of the stones, either solitarily or in groups. It resembles members of the family Bathyphelliidae Carlgren, 1932 or related families. Actiniaria spp. MATERIAL. LV-75-17, 55.4445ºN 167.2626ºE, depth 1819 m, one specimen photographed. LV-82-8, 55.3765°N 167.2639ºE, depth 668 m, three specimens photographed; LV-82-10, 55. 2879°N 167.3014ºE – 55.2898°N 167.2974ºE, depth 2807–2638 m, several specimens of 5 species photographed. LV-82-15, 61.1512°N 174.9148ºE – 61. 1774°N 174.8715ºE, depth 494–460 m, two specimens photographed; LV-82-16, 61.1869°N 174. 8397ºE – 61.1902°N 174.8347ºE, depth 373–356 m, five specimens photographed; LV-82-18, 61.1196°N 174.9676ºE – 61.1201°N 174.9635ºE, depth 670– 652 m, two specimens photographed. REMARKS. About 10 species of undetermined Actiniaria that were photographed but not collected and cannot be identified: 6 on the Vulcanologov Massif and 2–4 species on the Koryak slope. Most of them are burrowing species or small species living on the stones which were difficult to collect by the manipulator of the ROV. Order Corallimorpharia Family Corallimorphidae Hertwig, 1882 Corallimorphus cf. pilatus Fautin, White et Pearson, 2002 Fig. 5 J, K. Corallimorphus pilatus Fautin et al., 2002: 118; EashLoucks, Fautin, 2012: 9. MATERIAL. AMK-22-2310, 55.3896°N 167. 2616°E – 55.385°N 167.2566°E, depth 602–750 m, dredge 1; 55.3753°N 167.2468°E – 55.3833°N 167. 265°E, depth 580–750 m, dredge 2; eight specimens collected. AMK-22-2311, submersible Mir-1, dive 6/50: 55.4166°N 167.272°E, depth 410 m, sample 3; 55.4163°N 167.2721°E, depth 409 m, sample 4; 55. 4161°N 167.2723°E, depth 396 m, sample 5; 24 specimens collected. AMK-22-2320, submersible Mir-2, dive 15/48: 55.3858°N 167.2583°E, depth 524 m, sample 2, one specimen collected. LV-75-1, 55.4246ºN 167.2903ºE, depth 1053 m, one specimen photographed; LV-75-2, 55.4173ºN 167.2766ºE – 55.4165ºN 167.2749ºE, depth 381– 407 m, one specimen collected (sample 2) and many specimens photographed; LV-75-3, 55.4165ºN 167. 2735ºE – 55.4164ºN 167.2759ºE, depth 386–390 m, many specimens photographed; LV-75-4, 55.4165ºN 167.2749ºE – 55.4167ºN 167.2759ºE, depth 390– 399 m, many specimens photographed; LV-75-5, 55.4166ºN 167.2749ºE – 55.4166ºN 167.2755ºE, depth 372–394 m, one specimen collected (sample 2) and many specimens photographed; LV-75-6, 55. 4166ºN 167.2743ºE – 55.4165ºN 167.2762ºE, depth 49Actiniaria, Corallimorpharia and Zoantharia from the Western Bering Sea 372–396 m, many specimens photographed; LV75-7, 55.4174ºN 167.2747ºE – 55.4166ºN 167. 2752ºE, depth 421–409 m, many specimens photographed; LV-75-8, 55.4163ºN 167.2755ºE – 55. 4161ºN 167.2749ºE, depth 407–386 m, four specimens collected (sample 1) and many specimens photographed; LV-75-9, 55.4180ºN 167.2760ºE – 55.4161ºN 167.2742ºE, depth 424–349 m, many specimens photographed; LV-75-10, 55.4169ºN 167. 2744ºE – 55.4172ºN 167.2748ºE, depth 407–411 m, many specimens photographed; LV-75-11, 55. 3821ºN 167.2609ºE, depth 470 m, three specimens collected (sample 1) and many specimens photographed; LV-75-12, 55.3823ºN 167.2608ºE – 55. 3810ºN 167.2611ºE, depth 468–474 m, many specimens photographed; LV-75-13, 55.3822ºN 167. 2608ºE – 55.3826ºN 167.2605ºE, depth 466–472 m, one specimen collected (sample 1) and a few specimens photographed; LV-75-14, 55.3822ºN 167. 2611ºE – 55.3820ºN 167.2607ºE, depth 460–465 m, a few specimens photographed; LV-75-15, 55. 3822ºN 167.2612ºE – 55.3821ºN 167.2612ºE, depth 466–459 m, several specimens collected (sample 1) and many specimens photographed; LV-75-19, 55. 3822ºN 167.2625ºE – 55.3819ºN 167.2606ºE, depth 494–453 m, a few specimens photographed; LV-7520, 55.3824ºN 167.2618ºE – 55.3822ºN 167.2611ºE, depth 481–470 m, many specimens photographed; LV-75-21, 55.4812ºN 167.2572ºE, depth 2834 m, one specimen photographed; LV-75-22, 55.5100ºN 167.3240ºE – 55.5087ºN 167.3236ºE, depth 3561– 3545 m, five specimens photographed. LV-82-1, 55.4171ºN 167.2773ºE – 55.4165ºN 167.2763ºE, depth 386–382 m, several specimens collected (samples 3 and 7) and many specimens photographed; LV-82-2, 55.4167ºN 167.2764ºE – 55.4158ºN 167.2766ºE, depth 383–400 m, many specimens photographed; LV-82-3, 55.3827ºN 167. 2626ºE – 55.3816ºN 167.2608ºE, depth 492–464 m, several specimens collected (samples 1, 2 and 3) and many specimens photographed; LV-82-4, 55.3817ºN 167.2612ºE – 55.3820ºN 167.2611ºE, depth 465– 451 m, many specimens photographed; LV-82-8, 55.3814ºN 167.2617ºE – 55.3825ºN 167.2617ºE, depth 469–475 m, several specimens collected (samples 2 and 7) and many specimens photographed. REMARKS. The specimens are of moderate size, very abundant on the upper slope and top of the Piip Volcano at 372–1053 m. The white form (Fig. 5 J) with bright-white acrospheres at the tip of the tentacles dominates on the northern top, occurs near bacterial mats. The brown form with white acrospheres dominates at the southern top (Fig. 5K) and occurs directly on the seeps on bacterial mats. The species is hexamerous with up to five cycles of the marginal tentacles, 12 (two cycles) discal tentacles located in the endocoels of the first and the second cycles. Large specimens have about 12 discal and 49 marginal tentacles (the ratio is 1:4, as in C. pilatus). The height and diameter of the preserved specimens is up to 16 mm. There are 12 pairs of perfect mesenteries and very small miscrocnemes of third and fourth cycles. Corallimorphus pilatus appear to be most closely related to the present specimens, its original description is based on numerous specimens from 198–900 m in the eastern Pacific from British Columbia to Southern California. Subsequently it was found from much greater depths (up to 2000 m) (Eash-Loucks, Fautin, 2012). Some specimens reported here were photographed at great depth (3545– 3561 m) on the norther slope of the Piip Volcano, their morphology and external appearance are similar to those from shallower waters. Another deep-sea species (2834 m, one specimen in the photo) differs significantly from other specimens recorded on the Vulcanologov Massif in its dark bluish-brown color, body shape, high oral cone and, possibly, more numerous discal tentacles. Corallimorphidae sp. Fig. 5L. MATERIAL. LV-75-1, 55.4246ºN 167.2903ºE, depth 1053 m, one specimen photographed; LV-752, 55.4173ºN 167.2766ºE – 55.4165ºN 167.2749ºE, depth 381–407 m, many specimens photographed; LV-75-3, 55.4165ºN 167.2735ºE – 55.4164ºN 167. 2759ºE, depth 386–390 m, many specimens photographed; LV-75-4, 55.4165ºN 167.2749ºE – 55. 4167ºN 167.2759ºE, depth 390–399 m, many specimens photographed; LV-75-5, 55.4166ºN 167. 2749ºE – 55.4166ºN 167.2755ºE, depth 372–394 m, eight specimens collected (sample 2) and many specimens photographed; LV-75-7, 55.4174ºN 167. 2747ºE – 55.4166ºN 167.2752ºE, depth 421–409 m, many specimens photographed; LV-75-8, 55.4163ºN 167.2755ºE – 55.4161ºN 167.2749ºE, depth 407– 386 m, one specimen collected (sample 1) and many specimens photographed; LV-75-9, 55.4180ºN 167. 2760ºE – 55.4161ºN 167.2742ºE, depth 424–349 m, many specimens photographed; LV-75-10, 55. 4169ºN 167.2744ºE – 55.4172ºN 167.2748ºE, depth 407–411 m, many specimens photographed; LV75-12, 55.3823ºN 167.2608ºE – 55.3810ºN 167. 2611ºE, depth 468–474 m, many specimens photographed; LV-75-13, 55.3822ºN 167.2608ºE – 55. 3826ºN 167.2605ºE, depth 466–472 m, three specimens collected (sample 1) and many specimens photographed; LV-75-20, 55.3824ºN 167.2618ºE – 55.3822ºN 167.2611ºE, depth 481–470 m, many specimens photographed. LV-82-1, 55.4171ºN 167.2773ºE – 55.4165ºN 167.2763ºE, depth 386–382 m, many specimens photographed; LV-82-2, 55.4167ºN 167.2764ºE – 50 N.P. Sanamyan et al. 55.4158ºN 167.2766ºE, depth 383–400 m, several specimens collected (sample 7) and many specimens photographed; LV-82-3, 55.3827ºN 167.2626ºE – 55.3816ºN 167.2608ºE, depth 492–464 m, many specimens photographed; LV-82-4, 55.3817ºN 167. 2612ºE – 55.3820ºN 167.2611ºE, depth 465–451 m, many specimens photographed; LV-82-8, 55.3806ºN 167.2617ºE – 55.3825ºN 167.2617ºE, depth 485– 475 m, several specimens collected (sample 7) and many specimens photographed. REMARKS. This small (up to 1.5 cm in the height and the diameter of the tentacular crown) species occurs on both tops of the Piip Volcano together with larger Corallimorphus cf. pilatus and small Sagartiogeton rufus. The specimens are white, translucent; longitudinal strips of white filaments or gonads are visible through the cylindrical column. The pedal disc is expanded and wider than the column, often forms a kind of lobes and outgrows characteristic for pedal laceration. This species does not have discal tentacles characteristic for Corallimorphus; there are four cycles of marginal tentacles arranged hexamerously. Sometimes they occur directly among the bacterial settlements on the seeps. Several specimens have been collected. The greatest depth recorded from a photograph for this species is 1053 m (on the dead glass sponge Farrea sp.). Order Zoantharia Family Epizoanthidae Delage et Hérouard, 1901 Epizoanthus fatuus (Schultze, 1860) Fig. 6A. Palythoa fatua Schultze, 1860: 36. MATERIAL. LV-75-16, 55.5774ºN 167.3258ºE, depth 4277 m, one colony photographed; LV-7522, 55.5134ºN 167.3270ºE – 55.5087ºN 167.3236ºE, depth 3602–3534 m, three colonies photographed. LV-82-5, 55.2698ºN 167.2995ºE – 55.2738ºN 167.2974ºE, depth 3520–3435 m, two colonies collected (samples 7 and 8) and one colony photographed. REMARKS. Deep-water colonial zoantarian growing on the stem of glass sponge of the genus Hyalonema. The species is recorded in the abyssal zone on the northern and southern slopes of the Vulcanologov Massif and in the Komandor Graben from 3435 to 4277 m; two colonies were collected. The zooids densely cover the sponge stem composed of bundle of spicules. They extend from the lover part of the stem, along the whole its length, to the body of the sponge located on the top of the stem. They are also found on the dead stems which have no body of the sponge at the end (Fig. 6A) sometimes inhabited by other organisms (hydroids or sea anemones, Fig. 2A). Zooids are white, up to 2–3 cm high and have two cycles of the tentacles. Epizoanthus sp. Fig. 6B. MATERIAL. AMK-22-2311, submersible Mir1, dive 6/50, 55.4163°N 167.2816°E, depth 358 m, sample 1, 80 specimens collected. LV-75-2, 55.4169ºN 167.2755ºE, depth 381 m, several specimens photographed; LV-75-3, 55. 4160ºN 167.2732ºE – 55.4161ºN 167.2739ºE, depth 382–351 m, many specimens photographed; LV75-8, 55.4162ºN 167.2736ºE, depth 378 m, many specimens photographed; LV-75-9, 55.4155ºN 167. 2736ºE – 55.4161ºN 167.2742ºE, depth 394–349 m, many specimens photographed. LV-82-1, 55.4165ºN 167.2767ºE – 55.4160ºN 167.2743ºE, depth 382–349 m, many specimens collected (sample 7) and many specimens photographed; LV-82-2, 55.4160ºN 167.2769ºE, depth 372 m, many specimens photographed; LV-82-4, 55.3809ºN 167.2604ºE, depth 478 m, several specimens collected (sample 4) and many specimens photographed. REMARKS. The species forms continuous “carpets”, often near the settlements of Sagartiogeton rufus, on the most shallow-water zone of the northern top of the Piip Volcano from 349 to 394 m. The number of specimens reaches 60–70 per square decimeter, some of them were collected. Their zooids are yellow-orange, with cylindrical column up to 2–3 cm in height, encrusted with sediment particles and foraminifers; the tentacles are organized in two cycles. S. rufus and zoantharians are similar in size and color, are often located next to each other and can be confused. However, the settlements of S. rufus are sparser and other species can settle among them, while there are almost no other species of sea anemones among the zoantharians. Settlements of zoantharians were also recorded on the southern top of the Piip Volcano, but they are less numerous there. The deepest record is 478 m on the southern top of the Piip Volcano. Zoantharians not identified to family level Zoantharia spp. Fig. 6C. MATERIAL. LV-75-22, 55.5100ºN 167.3240ºE – 55.5087ºN 167.3236ºE, depth 3561–3545 m, several specimens photographed. LV-82-5, 55.2616ºN 167.3025ºE – 55.2647ºN 167.3014ºE, depth 3931–3879 m, one specimen photographed; LV-82-10, 55.2879°N 167.3014ºE, 51Actiniaria, Corallimorpharia and Zoantharia from the Western Bering Sea depth 2807 m; 55.2882ºN 167.3011ºE, depth 2778 m, one specimen photographed. REMARKS. Small white specimens on stones were photographed in the abyssal zone. On the southern slope of the Vulcanologov Massif, two species have been recorded: a group of at least 7 specimens with a long column covered with sediment particles (Fig. 6C), and solitary specimens with a short white column. Another smaller species with a short white column occurs in small groups on the northern slope of the Vulcanologov Massif. Discussion About 80 species sea anemones are reported of which 40 were collected (36 species of Actiniaria, two Corallimorpharia and two Zoantharia), other species were identified basing on photo and video records. 17 of them were identified to the species level (one basing on the photographs only), most of remaining species require description as new species. 33 sea anemones were identified to the genus level (12 basing on photographs only), seven of these genera are represented more than in one species (Edwardsia, Cribrinopsis, Urticina, Actinostola, cf. Halcampa, Amphianthus, Phelliactis). 18 families were identified, five of them only on the photographs (Relicanthidae, Edwardsiidae, Preactiniidae, Halcampidae, Halcampoididae). 16 families belong to the order Actiniaria (over 70 species), one family to the order Corallimorpharia (Corallimorphidae, two species in two genera) and one to Zoantharia (Epizoanthidae, two species of Epizoanthus and three not collected species on the photographs only). Only 13 species (11 species of Actiniaria, one of Corallimorpharia and one of Zoantharia) were previously known to science but have not been reported for western part of the Bering Sea and only two of them, Liponema brevicorne and Metridium farcimen, were reported for eastern part of the Bering Sea. Four species of the present material (Sicyonis denisovi, Sicyonis kuznetsovi, Ophiodiscus bukini and Tealidium konoplinorum) have been already described as new to science (Sanamyan et al., 2021) and they are known only for western part of the Bering Sea. Of the 17 species identified in the present work, 10 species (59%) are known from eastern Pacific Ocean (Supplement Table 2): Relicanthus daphneae, Ptychodactis patula, Liponema brevicorne, Actinostola faeculenta, Stomphia coccinea, Actinauge verrillii, Paracalliactis involvens, Metridium farcimen, Sagartiogeton californicus and Corallimorphus pilatus. Two latter species were previously treated as endemics for northeastern Pacific by Eash-Loucks and Fautin (2012: 49): “Species that mostly occur above 2000 m (Corallimorphus pilatus from 250 to 2026 m, and Sagartiogeton californicus from 73 to at least 1463 m) appear endemic to the northeastern Pacific.” These authors stated that the growing oxygen minimum zone (OMZ), naturally occurring in Northeast Pacific, poses the biggest threat to these species occurring within the depth range of the OMZ in the northeastern Pacific Ocean and said to have restricted geographical ranges. We discovered that range of geographical distribution of these species is much wider and they distributed also in northwestern Pacific, where they are especially nuFig. 6. A — Epizoanthus fatuus; B — Epizoanthus sp.; C — Zoantharia sp. from the southern slope of the Piip Volcano. Рис. 6. A — Epizoanthus fatuus; B — Epizoanthus sp.; C — Zoantharia sp. на южном склоне вулкана Пийпа.