Search

During the KuramBio expedition in 2012, macrobenthos samples were collected with an epibenthic sledge from 12 sites on the abyssal plain of the Northwest Pacific Basin adjacent to the Kuril-Kamchatka Trench (KKT) and on the western slope of the KKT, at depths between 4830 and 5780 m. In terms of the peracarid fauna, the NW Pacific abyss was found to be one of the richest and densely populated deep-sea regions of the World Ocean. With 482 species, 168 genera, 61 families and 5 orders, the superorder Peracarida was found to be the most diverse and one of the most abundant macrobenthic taxa in the collection. Of the taxa found, 3 genera and 386 (80%) species were apparently new to science, 30 genera and the family Dendrotionidae (Isopoda) being recorded for the first time in the NW Pacific. The peracarid fauna composition at the abyssal depths of the KKT region was typical of the open, non-isolated abyssal plain. The Isopoda proved the most diverse and abundant peracarid order (245 species, 61.3% of the individuals), followed by the Amphipoda (79 species, 19.6%), Tanaidacea (77 species, 9.1%), the Cumacea (70 species, 9.7%), and the Mysida (11 species, 0.23%). The highest peracarid abundance (up to 1047 ind./1000 m2) was recorded on the western slope of the trench, abundances at the abyssal plain being lower (125–639 ind./1000 m2). The peracarid distribution in the area studied was affected by a complex of various factors, the food availability reflected in the Particular Organic Matter (POM) flux belonging to the most important ones. Specifically, increases in the peracarid abundance and species richness corresponded in most cases with a high sediment organic carbon content or the high surface productivity level in the area. As indicated by the sediment composition, the food input to the deep-sea system apparently differed between the sites sampled. On the trench slope, accumulation of organic debris, transported down the slope from shallower regions, played an apparently major role. The abyss in the northern and in the southern parts of the area sampled is influenced by the high surface productivity, resulting from the regional hydrography. The area east of the Middle Kuril Islands is likely influenced by the organic material transported from the Sea of Okhotsk through the Kuril Straits.

In the samples of the expedition SokhoBio (Sea of Okhotsk Biodiversity Studies) arcturoid isopods were present at eight sites in the Kuril Basin of the Sea of Okhotsk (1685–3366 m), the Bussol Strait (2327–2358 m), and the western abyssal slope of the Kuril-Kamchatka Trench (KKT) (3371–3377 m). They were represented by eight species of three genera and two families, Antarcturus, Chaetarcturus (Antarcturidae), and Neastacilla (Arcturidae). Six species turned out to be new to science. The composition of fauna and distribution of arcturoids in the Kuril Basin and the adjacent regions are discussed. A list of all arcturoid species known from the Sea of Okhotsk and the adjacent waters off the Pacific coast of the Kuril Islands and the Southeastern Kamchatka at depths > 500 m is provided. In the abyss of the Sea of Okhotsk two species (Chaetarcturus cf. beddardi (Gurjanova, 1935) and Neastacilla birsteini sp. nov.) were found. Neastacilla birsteini sp. nov., the dominant species in the abyss of the Kuril Basin, is described herewith. The new species differs from all other species of the genus by the 6-articled antennae I. N. birsteini sp. nov. most closely resembles N. anophthalma (Birstein, 1963) comb. nov. nov. Both species can be distinguished from all other species of the genus by the absence of eyes and a long article 5 of antenna I which is longer than articles 1–3 together. N. birsteini sp. nov. differs from N. anophthalma in the following characters: the pleon of the new species is 1.5 times longer than pereonite 4 and has an elongated distal part with a notch at the apex; the pereopod I carpus is 3.2 times as long as wide.

The deep-sea Munnopsidae Lilljeborg, 1864 of the Kuril Basin of the Sea of Okhotsk, the Bussol Strait, as well as the western abyssal slope of the Kuril-Kamchatka Trench (KKT) off the Bussol Strait were studied. The material was collected during the expedition SokhoBio (Sea of Okhotsk Biodiversity Studies) in the summer of 2015. The first data on the composition and distribution of the family Munnopsidae from the SokhoBio samples are presented. In total 2190 individuals of Munnopsidae from 53 species, 26 genera and seven subfamilies have been collected at 19 of 21 C-EBS stations at all 11 sites of the SokhoBio expedition. The most abundant subfamily in the samples was Ilyarachninae Hansen, 1916 (36%), followed by Eurycopinae Hansen, 1916 (29%). In the Kuril Basin 39 species of 20 genera and 5 subfamilies were found, the main portion of munnopsids here was represented by the Ilyarachninae (39%), followed by the group of genera incertae sedis (31%) and Eurycopinae (27%). The abyssal munnopsid fauna of the Kuril Basin is an intermediate in terms of diversity and species richness between the adjacent studied abyssal areas, the Sea of Japan and the open abyssal of the KKT. Half of the collected species, 27 species (51%) are shared with the KKT area, 22 species (41.5%) are common to the Kuril Basin and the Pacific sites. About 80% of the collected species are new to science. One of the new species, Gurjanopsis kurilensis sp. nov. is described herein. Gurjanopsis Malyutina and Brandt, 2007 is the only genus within the Munnopsidae having a posteromedial notch in the pleotelson containing tiny uropods and the anus. A similar notch in the pleotelson containing uropods within Janiroideа Kussakin, 1967 is known only in species of Jaera Leach, 1814 (Janiridae G.O. Sars, 1897). The male pleopods of Gurjanopsis which cover the pleopodal cavity of the pleotelson are unusual for the family. This “operculum” is formed by the small pleopods 1 and 2 and the enlarged exopods of pleopods 3. This is similar to the pleopodal structure found in the primitive asellote superfamilies Aselloidea Latreille, 1802 and Stenotrioidea Hansen 1905, while in Janiroideа only pleopods 1 and 2 are operculate. The new species is the third species of the rare genus Gurjanopsis and the first record of the genus, previously only known from the deep-sea of the Arctic and the Antarctic, for the Pacific Ocean. The finding a species of Baeonectes Wilson, 1982 in abyssal depths of the Kuril Basin is the deepest record of the genus.

Macrofauna (46,343 invertebrates from 41 taxa) were collected by means of a camera-epibenthic sledge (C-EBS) during the expedition SokhoBio (Sea of Okhotsk Biodiversity Studies) on board of the RV Akademik M.A. Lavrentyev in 2015. In total 11 sites and 22 stations were sampled at bathyal and abyssal depths ranging from 1696 m to 4798 m in the Kuril Basin of the Sea of Okhotsk (16 stations), the Bussol Strait (two stations) and western slope of the Kuril-Kamchatka Trench (KKT) (four stations). Polychaetes occurred most frequently in the samples with 17,546 individuals, followed by Peracarida with 14,099 individuals (5625 isopods, 3887 amphipods, 3225 tanaids, 1269 cumaceans, and 90 mysids), Copepoda (4679 ind.) and Bivalvia (3999 ind.). Numbers of individuals ranged between 140 at station 3–10–6383 at station 7–3. The numbers of taxa per station were smallest at station 3–10 (4 taxa) and highest at station 2–7 (31 taxa). Peracarida were the most common malacostracan crustaceans recorded, with Isopoda comprising 40% of all peracarids within this fraction, followed by Amphipoda with 27%, Tanaidacea with 23%, Cumacea with 9% and Mysida with 1%. At station 3–10, not a single peracarid was sampled. Isopoda dominated most of the stations, especially in the abyssal sites of the Kuril Basin. Amphipoda occurred in higher numbers in the Bussol Strait at site 8 as well as at Pacific station 9-7. In the SokhoBio area, studied macrofauna was distributed very patchily. In terms of diversity and composition the abyssal macrofauna of the Kuril Basin shows an intermediate state between the adjacent studied abyssal areas: the semi-isolated Sea of Japan and the open abyssal plain of the Kuril-Kamchatka Trench (KKT) area.

Eurycope producta Sars, 1868 and Eurycope inermis Hansen, 1916 are two widely distributed and highly abundant isopod species complexes within Icelandic waters, a region known for its highly variable environment. The two species complexes have bathymetric depth ranges from 103 to 2029 m (E. producta) and from 302 to 2113 m (E. inermis). Molecular evidence was used for species delimitation within these species complexes by analyzing nuclear (18S rDNA, H3) and mitochondrial (16S rDNA, COI) sequence data. Tree-based methods (BI and ML) and four species delimitation methods (ABGD, GMYC, NDT, PTP) were applied, in order to disentangle the two species complexes. A total of eight and four species clades could be identified within samples of the E. producta and E. inermis complexes and respectively included the closely related species E. dahli Svavarsson, 1987; E. hanseni Ohlin, 1901; and E. cornuta Sars, 1864. The morphological findings coincide with the observed molecular species clades. The elucidated species clades were geographically and bathymetrically much more restricted than previously assumed. Eight species clades featured depth spans of less than 400 m and only four species clades featured depth spans of 1000 to 1500 m. Only two species clades (E. producta sensu stricto and E. inermis sensu stricto) were found on both sides of the Greenland-Scotland Ridge. Further, species distribution maps were generated using random forest, to predict potential distributional patterns for the resolved species clades of the two species complexes. We present the first attempt of combining morphological, molecular, and species distribution models in marine isopods thus far.

Since the 1990s, the marine benthos of the Greenland–Iceland–Faeroe (GIF) Ridge has been sampled through the BIOICE (Benthic Invertebrates of Icelandic waters) and subsequent IceAGE (Icelandic Marine Animals: Genetics and Ecology) projects. Isopod crustaceans formed one of the prominent macrofaunal groups. Most isopod families occurred on both sides of the ridge, but showed side-specific abundance patterns reflecting known distribution from the literature. Our results from 35,536 isopod specimens from 55 epibenthic sled stations show a depth pattern at the family level indicating typical shallow water families like, for example, Paramunnidae or typical deep-water families like, for example, Haploniscidae and Ischnomesidae, while other families did not show a clear depth trend. We hypothesize that the ridge influences the distribution of the families through its effects on the hydrography and sediment characteristics. Total organic carbon (TOC) and mud content significantly explained isopod family distributions, possibly reflecting different habitat use and lifestyle (e.g., infaunal, epifaunal). Our analysis of a subset of 27 selected BIOICE and IceAGE stations and 100 isopod species (22,574 specimens), mostly covering the upper 1000 m depths between Iceland and Norway along the Iceland–Faeroe Ridge (IFR), resulted in four main species assemblages differing in species diversity. Whereas north of the IFR, we found 76 species; south of the IFR, we found 52 species; 40 species occurred both north and south of the IFR. Although the subset of selected stations is limited to a comparably small portion of the IceAGE sampling grid and to a comparably restricted depth range of the upper 1000 m, our result shows the slope area of Northeast Iceland and around the Faeroes and the Norwegian Channel with the highest number of species, especially stations in the thermocline between 400 and 800 m depth, where we observed the turnover from shallow to deep-water faunal elements.

Coxicerberus fukudai (Ito, 1974) (Isopoda) is redescribed from Korean and Japanese localities. Molecular analysis based on two mitochondrial markers (mtCOI and Cytb) of the studied populations shows two diverged lineages, reflected in high (10.5% and 9.5%) pairwise differences and high haplotype diversity. One of the clades is shared by Korean and Japanese populations with little divergence rate (0.02% and 0.03%), and another is only found in Korea. We failed to find any consistent morphological differences across the examined populations, probably indicating the existence of cryptic species. We also examined the possible influence of the endosymbiotic bacterium Wolbachia on the haplotype diversity. Infection with the bacterium shows a distinct distribution pattern, with all the southern Korea populations being infected, whereas the northern populations are not.

The present paper provides data of the world-wide distribution, abundance and diversity of the rare deep-sea munnopsid genus, Acanthocope Beddard, 1885 and presents an identification key to the 18 known species of Acanthocope. Two new species, Acanthocope puertoricana sp. nov. from the tropical abyssal area near the Puerto Rico Trench and Acanthocope galaica sp. nov. from the Galicia Bank, Northeastern Atlantic are described. Additionally, Acanthocope annulatus Menzies, 1962 and Acanthocope eleganta Malyutina and Brandt, 2004 have been collected in the Puerto Rico Trench area, whereas Acanthocope galatheae Wolff, 1962 were collected along a latitudinal transect crossing the tropical abyssal North Atlantic during the Vema-TRANSIT expedition. A. puertoricana is most similar to A. carinata Chardy, 1972 from the Northwestern Atlantic and differs from the latter by: a more slender body; a broader head; a more slender and shorter lateral projections of the pleotelson; the presence of ventral spines on natasome; and a longer uropod. A. galaica sp. nov. is most similar to A. spinicauda Beddard, 1885 and differs from the latter by having a more elongate pleotelson with almost straight lateral margins between lateral spines, whereas the margins are more convex in A. spinicauda. Pereopods 5 and 6 of A. galaica have broader carpi than in A. spinicauda.

We analyzed composition and variations in benthic macrofaunal communities along a transect of the entire length of the Vema-Fracture Zone on board of RV Sonne (SO-237) between December 2014 and January 2015 in order to test whether the Mid-Atlantic Ridge serves as a barrier limiting benthic taxon distribution in the abyssal basins on both sides of the ridge or whether the fracture zone permits the migration of species between the western and eastern abyssal Atlantic basins. The Puerto Rico Trench, much deeper than the surrounding abyssal West Atlantic, was sampled to determine whether the biodiversity of its hadal macrofauna differs from that of the abyssal Atlantic. The composition of the macrofauna from the epibenthic sledge catches yielded a total of 21,332 invertebrates. Crustacea occurred most frequently (59%) with 12,538 individuals followed by Annelida (mostly Polychaeta) (26%) with 5491 individuals, Mollusca (7%) with 1458 individuals, Echinodermata (4%) with 778 individuals, Nematoda (2%) with 502 individuals and Chaetognatha (1%) with 152 and Porifera (1%) with 131 individuals. All other taxa occurred with overall less than ten individuals (Hemichordata, Phoronida, Priapulida, Brachiopoda, invertebrate Chordata, Echiurida, Foraminifera (here refereed to macrofaunal Komokiacea only), Chelicerata, Platyhelminthes). Within the Crustacea, Peracarida (62.6%) with 7848 individuals and Copepoda (36.1%) with 44,526 individuals were the most abundant taxa. Along the abyssal Vema-Fracture Zone macrofaunal abundances (ind./1000 m 2 ) were generally higher on the eastern side, while the highest normalized abundance value was reported in the Puerto Rico Trench at abyssal station 14-1 2313 individuals/1000 m 2 . The lowest abundance was reported at station 11-4 with 120 ind./1000 m 2 located at the western side of the Vema-Fracture Zone. The number of major macrofaunal taxa (phylum, class) ranged between five (stations 12-5, 13-4 and 13-5 at hadal depths in the Puerto Rico Trench) and 14 (station 9-8) in the western abyssal basin of the Vema-Fracture Zone. Differences are seen in the distribution of Porifera at macrofaunal level between eastern and western sides of the Vema-Fracture Zone. Macrofaunal composition of the study area is compared with data from other expeditions in the Atlantic and the northwest Pacific Ocean.

Two new abyssal species of Dendrotionidae are described: Dendromunna kurilensis sp. nov. from the Northwest Pacific Basin to the east of the Kuril–Kamchatka Trench and D. okhotensis sp. nov. from the Kuril Basin of the Sea of Okhotsk. The new species represent the first records of the family for the Northwest Pacific and the first records of the genus for the North Pacific. The new species differ from the remaining species of Dendromunna by the extremely long antennae and pereopods (antenna I is about 0.7–0.8 body length, article 4 of antenna II is about 0.6–0.7 body length, bases of pereopods are about 0.2–0.3 body length), the male pereopod I with concave lateral margins, short pereonite 1 (

The asellote family Gnathostenetroididae Kussakin, 1967 is reported for the first time from Australian waters. Four new species of Gnathostenetroides Amar, 1957 from the Great Barrier Reef are described. The genus Maresiella Fresi and Scipione, 1980 is here placed into synonymy with Gnathostenetroides and a new diagnosis is given for Gnathostenetroides together with a key to the 12 species and a map of the distribution of the genus. The genus Dignatroides Stock and Vonk, 1990 is placed into synonymy with Caecostenetroides Fresi and Schiecke, 1968, and a new composition of the family Gnathostenetroididae, the updated diagnosis and a key to the three genera are provided.

As part of the New Zealand government Ocean Survey 20/20 programme (OS 20/20, 2006–2013), samples from the Chatham Rise and Challenger Plateau collected in 2007 were analysed to determine the effects of key environmental parameters, in particular sediment and water mass properties, on spatial changes in the community structure (abundance, diversity and community composition) of bathyal asellotan isopods. Benthic collections were obtained in austral autumn (May/June 2007) and included a total of 21 epibenthic sledge samples taken from the upper slope between 218 and 1239 m. Due to the contrasting environmental settings between the Chatham Rise and Challenger Plateau, in terms of surface productivity and habitat heterogeneity, we expected the abundance, regional (or gamma-) diversity and community composition of benthic isopods to significantly differ between the two regions, and furthermore local (or alpha-) diversity and abundance (density) to decrease with increasing depth. Consistent with our assumptions, multivariate PERMANOVA analysis revealed a clear distinction in species composition between the Chatham Rise and Challenger Plateau with satellite surface chlorophyll (Chl) a and bottom temperature being the main environmental drivers. In contrast to previous benthic studies from the same sampling campaign, however, differences in isopod density and diversity between the two regions were not significant, either at species, or generic and family level. In addition, no depth-related changes in abundance and diversity could be observed at any hierarchical level. Instead, isopod densities at species and generic level were positively correlated with satellite surface Chl a and %silt, whilst species and generic diversity could be positively linked to the amount of total organic matter (TOM) in surficial sediments. In total, 97 asellote species in 54 genera and 15 families could be identified from both regions, of which 90.7% were likely new species. Species diversity was average to high when compared to other regions in the Northern and Southern hemispheres. However, neither for Chatham Rise nor for the Challenger Plateau did the species accumulation curves reach an asymptote, indicating that additional samples are required to provide more robust diversity estimates.

The benthos of the Kuril–Kamchatka Trench (KKT) was sampled during the KuramBio II expedition on board the RV Sonne in 2016. Macrobenthos was, for the first time, collected in the KKT hadal zone using an epibenthic sledge. Isopod crustaceans were one of the dominant taxa, and Munnopsidae was the most abundant and diverse asellotan family, comprising 49% of all Isopoda. During the expedition, a total of 67 species of 24 genera from eight subfamilies of Munnopsidae were collected, including 41 species of 15 genera from 18 hadal stations. In general, the taxonomic diversity of the munnopsid fauna in the KKT hadal zone was lower than that of the Northwest Pacific (NWP) abyssal fauna adjacent to the KKT. Two subfamilies, Lipomerinae and Acanthocopinae, were not found in the hadal zone. Most of all collected munnopsid individuals (92%) belonged to the three subfamilies: Eurycopinae (42%; 15 species), Betamorphinae (33%; four species), and Storthyngurinae (17%; two species). The rest of all munnopsid individuals (8%) belonged to the subfamilies Ilyarachninae, Munnopsinae, Syneurycopinae, and to a group of incertae sedis genera. The eight most numerous species representing the three most widely distributed and speciose genera—Eurycope, Betamorpha and Rectisura—encompassed 78% of all munnopsid individuals. The study of the Munnopsidae collected during the four expeditions (SoJaBio in 2010, KuramBio in 2012, SokhoBio in 2015 and KuramBio II in 2016) extended the known diversity of the munnopsid species in the KKT area from 39 described species of 14 genera to 157 species of 36 genera. Most collected species (87%) were new to science. The fauna richness showed a tendency to decrease from the open abyssal towards the hadal zone of the KKT and towards the semi-isolated abyssal Kuril Basin of the Sea of Okhotsk, and especially towards the more isolated abyss of the Sea of Japan. A comparison of the munnopsids from NWP and those from other oceans showed their similar composition with the same dominant subfamilies. The main difference between the abyssal munnopsids from the NWP and from the Atlantic sector of the Southern Ocean was the proportion of the Lipomerinae (2% vs. 16% of munnopsid individuals, respectively). A trend of reduction in the munnopsid diversity from abyssal to hadal depths, similar to that in the KKT, was also revealed in the Puerto-Rico Trench.

In the past seven years, the biology of the bathyal, abyssal and hadal faunas of meio- macro-, and megabenthos of the northwestern (NW) Pacific have been intensively investigated by Russian and German partners. A total of four joint expeditions with both RV Akademik M.A. Lavrentyev as well as RV Sonne have provided data on the systematic, evolution and biogeography of the deep-sea fauna of the Sea of Japan, Sea of Okhotsk, the Kuril-Kamchatka Trench (KKT) and the NW Pacific open abyssal plain. Goals of these expeditions were to study the biodiversity, biogeography and trophic characteristics of the benthic organisms in different NW Pacific deep-sea environments, to compare more isolated deep-sea basins with more easily accessible ones and to test whether the hadal of the KKT isolates the fauna of the Sea of Okhotsk to the fauna of the open NW Pacific area. An outline of some important results in presented. These data build the basis of the Beneficial ( B iog e ography of the n orthwest Pacific fauna. A benchmark study for e stimations o f alien i nvasions into the Ar c tic Ocean i n times of r a pid c l imate chance) project which aims to deliver a sound biogeographic baseline study of the NW Pacific area. These data will serve as a solid basis and benchmark for predicting potential species invasions supported by the retreat of Arctic Ocean sea ice. Thus our data will be beneficial for the assessment of state and quality of the Arctic marine ecosystem in a changing environment.

Abyssal macrofaunal composition of 21 epibenthic sledge hauls from twelve stations taken in the Kuril–Kamchatka Trench (KKT) and at the adjacent abyssal plain, Northwest Pacific, is presented. Sampling with the fine meshed epibenthic sledge yielded higher abundances and species richness than was reported from previous expeditions from board of RV Vityaz. In total 84,651 invertebrates were sampled with RV Sonne between July and September of 2012 (31,854 invertebrates if standardised for 1000 m2 trawled distances) from 41 taxa of different taxonomic ranks (15 phyla, 28 classes, 7 orders) were sampled from a trawled area of 53,708 m² and have been analyzed. Few taxa were frequent and most taxa were rare in the samples, twelve taxa occurred with more than 1% frequency. Of these, the Polychaeta were most abundant followed by the benthic Copepoda and Isopoda. Total numbers of individuals varied between stations and were highest with 4238 individuals at station 2-10 close to the KKT in 4865 m depth and lowest with 374 individuals at station 6-11 in 5305 m depth. At this station also the lowest number of taxa occurred (18 taxa) while the highest number occurred with 31 taxa at station 3-9 in 4991 m depth. Numbers of individuals decreased with increasing depth between 4830 and 5780 m. Crustaceans of the superorder Peracarida were one of the dominating taxa with four orders occurring frequently in most samples. In total, Isopoda were most important and occurred with 59% of all peracarid orders sampled, followed by Amphipoda with 21%, Tanaidacea with 11%, Cumacea with 9%, and Mysidacea with

The isopod family Munnopsidae Lilljeborg, 1864 was the most diverse and species richest family among all macrobenthic organisms collected during the expedition KuramBio in the abyssal area off the Kuril–Kamchatka Trench (R.V. Sonne, 2012). The munnopsid genus Microcope Malyutina, 2008 , represented by two species, was one of the most abundant and frequent isopod genera sampled at all stations. Microcope ovata ( Birstein, 1970 ), the only known Pacific species of Microcope to date, is redescribed based on the new collections, since the types of the species were lost. Descriptions of a new species from the KuramBio samples, Microcope stenopigus sp. nov. and a new species from the opposite side of Pacific Ocean, from the southeastern Australian slope, Microcope justi sp. nov., are presented herein. These findings increase the number of described species of Microcope to five and extended the geography of the genus from the previously known South Atlantic, Antarctic and the northwestern Pacific to the new localities from the southwestern Pacific. The depth range for the genus was also extended from 2014–7370 m, to 427–7370 m. A map of the distribution of the genus Microcope and a key to the described species of Microcope are provided.

This study focusses on the isopod biodiversity in the abyssal area southeast of the Kuril–Kamchatka Trench. The KuramBio (Kuril–Kamchatka Biodiversity Studies) expedition in summer 2012 collected altogether 10,169 isopods from 21 C-EBS hauls at 12 stations, belonging to 19 families, 73 genera and 207 species from the depth range between 4830 and 5780 m. Munnopsidae and Desmosomatidae were the most abundant and species-rich families, Eurycope (Munnopsidae) and Macrostylis (Macrostylidae) the most abundant genera. An nMDS plot on the basis of the Cosine similarity index reveals no clear pattern and all hauls to be different from each other. We compared our data with 12 stations from the same depth range sampled by the Russian RV Vityaz about 50 years ago and were able to identify several species collected by the RV Vityaz . The identified isopod species belonged to the families Munnopsidae, Macrostylidae, Haploniscidae, Desmosomatidae, Ischnomesidae and Nannoniscidae. Of the 333 individuals collected by the RV Vityaz , Haploniscidae and Munnopsidae were the most abundant families. Desmosomatidae were only represented by Vityaz samples are not approaching an asymptote, indicating that even after repeated sampling just a part of the local fauna has been recorded so far.

Individual wood fragments obtained from Agassiz trawl samples in the abyssal plain area off the Kuril–Kamchatka Trench were analysed for faunistic components. Out of seven pieces of wood collected, only five harboured fauna and each showed distinctively different colonization patterns. In total, 257 specimens, mainly belonging to the phyla Arthropoda, Nematoda, Mollusca and Annelida, were collected from the available pieces of wood. While wood-boring bivalves of the genus Xylophaga, generally seen as opportunists among wood-converting organisms, were present at nearly all stations, the overwhelming majority of taxa found were restricted to individual pieces of wood. A fresh piece of wood from a site opposite to the Tsugaru Strait, was the most heavily colonized. The presence of shallow or even putative fresh-water taxa beside truly deep-water components possibly suggests a recent sinking of that particular wood fragment and demonstrates the role of such ephemeral organic objects in deep-sea ecosystems as energy-rich feeding grounds and potential distributional stepping stones. Detailed studies of driftwood communities on single sunken wood fragments from deep oceans are limited. The present data not only demonstrate a tolerance of some taxa to changes in physical parameters, such as hydrostatic pressure, salinity and temperature, but also indicate a higher biodiversity on fresher wood pieces compared to wood which already underwent decomposition processes. It is, however, not clear whether the species diversity was linked to the type of wood, since exhaustive analyses on the wood pieces themselves were not conducted.

Angelika Brandt, Marina V.Malyutina (2015): The German-Russian deep-sea expedition KuramBio (Kurile Kamchatka biodiversity studies) on board of the RV Sonne in 2012 following the footsteps of the legendary expeditions with RV Vityaz. Deep-Sea Research II 111: 1-9, DOI: 10.1016/j.dsr2.2014.11.001

The abyssal macrobenthos of the Kuril–Kamchatka Trench (KKT) area was sampled for the first time using a fine-meshed camera-epibenthic sledge (C-EBS) during the German–Russian KuramBio expedition 2012 (RV Sonne, 223 cruise). Crustaceans of the order Isopoda were one of the dominant macrobenthic taxa, and the family Munnopsidae was the most abundant and diverse among 17 collected asellotan families, comprising about 48% of all isopods. During the KuramBio expedition no less than 80 species of 28 genera and eight subfamilies of Munnopsidae were collected with 21 EBS hauls at 12 stations. About 80% species are new to science and half of the genera and the subfamily Lipomerinae are recorded for the first time in the Northwest Pacific. The most abundant and speciose subfamily was Eurycopinae (58% of all specimens and 29 % of species), followed by Ilyarachninae (12% and 16%). Most species are rare and occur with low abundance at one or few stations. Ten most numerous species belonging to the genera Eurycope (5 species), Microcope (2), Disconectes (1), Ilyarachna (1) and Aspidarachna (1) comprised 68% of all munnopsids. The species Eurycope sp.1 and Microcope ovata ( Birstein, 1970) were the most abundant and frequent species, occurring at all stations. The highest abundance of Munnopsidae and high diversity, with 32 species, occurred at station 3–9 on the western slope of the KKT. The cluster analysis of the Bray–Curtis similarity shows a low similarity between stations. The least similar was station 1-10, with only 26% similarity with other stations. Low similarity also characterized station 3–9 (34%). The comparison with known data revealed differences in species composition of Munnopsidae of the abyssal plain of the KKT area and the fauna of adjacent bathyal and hadal zones. Similar ratios of the munnopsid subfamilies and genera and some similar species have been revealed for the KuramBio and ANDEEP areas.

Reductogonium iroquois gen. nov. sp. nov., a new genus and species of paramunnid isopods from the Northwest Pacific open abyssal plain to the east of the Kuril-Kamchatka Trench, is described based on materials from the KuramBio expedition (2012). The new genus is distinguished from other paramunnid genera by its reduced pereonite 7 that lacks appendages in adult individuals (one seta is presented instead of the pereopod VII on its position). It is also distinguished by its head, which has a medial crest bearing a tuft of setae on its posterior part, and by the extremely long articles of antennae and pereopods. The unusual paedomorphic features of the new genus might be adaptations to deep-sea conditions. Paedomorphosis was recorded for different taxa of deep-sea animals. The reduction of the last pair of pereopods, which corresponds to the state of manca stages, was observed independently in different families and orders of Isopoda. Finding a new species and a new genus of the Paramunnidae with paedomorphic features confirmed that this phenomenon is a common evolutionary strategy for deep-sea Asellota.

Areas of the Northwest (NW) Pacific have been investigated in the last century from board of the Russian RV Vityaz. During the past decade intensive collaboration between German and Russian scientists has yielded a wealth of precious material partly from unknown areas. The samples are comparable and were retrieved using comparative epibenthic sledge (EBS) deployments following a standardized sampling approach. In the present paper we investigate a large number of EBS samples (76) from a widespread geographic area. Macrofaunal high-taxonomic-level taxa composition is analysed based on four joint expeditions performed between 2010 and 2016, led by German and Russian teams in the NW Pacific, the Sea of Japan, the Sea of Okhotsk, and the Kuril-Kamchatka Trench and adjacent abyssal plain. In total, 410,279 invertebrates were sampled with an epibenthic sledge and more than half of all animals were collected in the Sea of Japan (240,803 individuals). Arthropods, represented by crustaceans, were dominant throughout all geographic areas (199,044 ind.), followed by Annelida (84,751 ind.), Echinodermata (46,317 ind.), and Mollusca (43,391 ind.). Within these phyla, eleven taxa occurred with more than 10,000 individuals in the samples from all geographic areas. The most numerous were the Peracarida (104,139 ind., represented by Isopoda [42,511 ind.], Amphipoda [29,375 ind.], Cumacea [16,364 ind.], Tanaidacea [15,889 ind.]), followed by Polychaeta (84,751 ind.), Copepoda 76,496 ind., Bivalvia (36,286 ind.), Ophiuroidea (34,818 ind.), Nematoda (24,968 ind.), Ostracoda (11,304 ind.), and Holothuroidea (10,772 ind.). The pattern of occurrence per taxon varied between geographic areas. In general, Bivalvia and Holothuroidea were more frequently recorded from hadal stations, but no significant differences could be observed between geographic areas (Sea of Japan, Sea of Okhotsk, and open NW Pacific) at high level taxa (classes, subclasses, superorders) when community composition is compared and depth differences are taken into account. However, significant differences between all depth zones (p