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The large-scale dispersal of deep-sea harpacticoid copepods is an increasing focus for ecological studies. A fundamental prerequisite for monitoring and explaining their geographical distribution is precise descriptions of their morphology. Four new, closely related species of the family Paramesochridae (Copepoda, Harpacticoida) were found in the deep sea of the Pacific (San Diego Trough and off Chile), the Atlantic Ocean (Porcupine Abyssal Plain and Angola Basin), and the Atlantic and Indian Ocean sectors of the Southern Ocean (Weddell Sea and off Crozet Island). The discovery of Emertonia berndi sp. nov., E. hessleri sp. nov., E. ilse sp. nov., and E. serrata sp. nov. increases the number of known deep-sea species in this genus to ten. The new species are placed in Emertonia Wilson, 1932 because of their one-segmented endopods on the second and third swimming legs. The presence of a two-segmented endopod on the fourth swimming leg allocates them to the “andeep-group” within this genus. The four species can be distinguished from their congeners by the strongly serrated spines on the exopods of their swimming legs and an outwardly directed flexible seta on the exopod of the fifth leg. It is conveivable that these two specific characters evolved only once in the genus Emertonia. Their apparently cosmopolitan distribution covers thousands of kilometres and spans all major oceans. This biogeographical pattern may be explained by resuspension events followed by passive transport by benthic currents. Discrepancies in their dispersal ranges may be a result of changing geological and oceanographic boundaries.

The marine environment of the tip of the Antarctic Peninsula is characterised by three oceanographically distinct regions for which we linked continental-slope meiofaunal patterns and environmental drivers on a large scale (100–300 km among ecoregions). Samples for meiofauna communities and sediment analyses were collected with a multicorer, water-column data were derived from water samples and CTD recordings. Meiofauna communities including individuals from 19 higher taxa were compared to a set of 16 environmental variables. We detected significant differences between the communities of Weddell Sea and those of Bransfield Strait and Drake Passage. The amount of phytopigments in the sediment, their freshness and the silt and clay content were driving factors for this separation. The highest meiofauna abundances were found at slopes in the Weddell Sea. Food banks may facilitate high standing stocks. There, the highest ever recorded copepod percentages for the Antarctic were related to the highest phytopigment contents while nematodes were extremely abundant even in deeper sediment layers at stations with fresh organic material. For Bransfield Strait and Drake Passage a sampling scheme of slopes and adjacent troughs was applied. The two regions were divided into three geographical “areas” with the two “habitat” types investigated for each area. Multivariate non-parametric permutational analysis of variance (PERMANOVA) showed that in Bransfield Strait slope and trough meiofauna communities differed significantly in all geographical areas while in Drake Passage this was only the case in the East. These differences were explained best by the regionally and topographically distinct characteristics of 7 out of 11 water-column and sediment-bound factors related to sediment grain size, food quantity and quality, water temperature and salinity. Environmental drivers of the benthic habitat are dependent on large-scale oceanographic conditions and are thus sensitive to changes in water mass characteristics, sea-ice cover and the related primary production.

A history of the Marine Zoology Department at the Senckenberg Society for the Study of Nature (Senckenbergische Naturforschende Gesellschaft) has not yet been published. Still, there is no lack of documentation of research activities at the Senckenberg Research Institute and Natural History Museum. Marine zoology studies began with Eduard Ruppell (1794–1884) after his admission to the Senckenberg Society in 1818, one year after its foundation, and his collections of fishes, molluscans and crustaceans from the Mediterranean made in 1820. During the nineteenth century, further progress in marine zoology studies was slow and serious interest in the study of marine organisms expanded significantly only during the twentieth century after the foundation of the marine station at Wilhelmshaven in 1928. The amount of marine biology and geology literature originating from researchers associated with the Senckenberg has become overwhelming and the dwarfs once standing on the shoulder of giants have become giants themselves. In this article, we present the Marine Zoology Department, its sections and assess the most important researchers associated with the Senckenberg Research Institute including the founders of the sections and their place in two centuries of history since the foundation of the Senckenberg Society in 1817.

Particulate organic carbon (POC) export fluxes generally reflect patterns of primary production in the upper ocean, sinking to the seabed and acting as a food source for benthic organisms. Data on meiobenthic communities from two SYSTem COupling cruises (SYSTCO) in the deep Southern Ocean (RV Polarstern ANT-XXIV/2, north–south transect along the prime meridian, and ANT-XXVIII/3, east–west transect along the Polar Front) were combined with surface and benthic environmental parameters, as well as POC flux estimates based on satellite measurements. It was tested to what extent meiofaunal communities were determined by prevailing conditions of an east–west increase in net primary productivity (NPP) and bottom Chlorophyll a (Chla) concentration, and a westwards, divergently decreasing estimated POC flux. Nematodes dominated the meiofauna (84.4–92.4%) and occurred with a westward increase in relative abundance and density for the ANT-XXVIII/3 stations, associated with a parallel increase in NPP and Chla. Nematode biomass was negatively correlated to the estimated POC flux. Along the north–south transect no significant correlation was found but higher estimated POC fluxes at stations south of the Polar Front were associated with higher meiofauna diversity and density at higher taxon level, while stations located at the Polar Front, which were associated with lower POC fluxes, contained communities with lower diversity and density.

Two new species of Emertonia (Paramesochridae) were collected during cruises of RV “Meteor” to the Great Meteor Seamount (1998), the Angola Basin (2000) and the Guinea Basin (2005) and of RV “L’Atalante” to the Pacific Nodule Province (2004). The widely distributed Emertonia clausi sp. n. was represented by 13 individuals found in depths from 4,005 m to 5,389 m in Atlantic and Pacific abyssal plains. A revision of material from the plateau and the slope of the Great Meteor Seamount revealed that E. clausi sp. n. is one of the rare eurybathic species of Harpacticoida, as it was also found at the plateau and the slope of the seamount. Emertonia ingridae sp. n. was represented by two individuals reported only from the Atlantic Guinea Basin at 5,139 m and 5,167 m water depth. The new species are placed in Emertonia due to their characteristic swimming legs with 1-segmented endopods in P2–P4 with one apical setal element. E. clausi sp. n. and E. ingridae sp. n. are closely related species, as they have many characters in common, but differ in subtleties. Unique features of both, E. clausi sp. n. and E. ingridae sp. n., are the single seta in enp2 P1 and the structure of seta V of the furcal rami, which changes from robust to flexible after approximately 0.4 × the length of the seta. The robust part of the seta carries in E. ingridae sp. n. two spinule pairs, in E. clausi sp. n. three pairs, the distal pair being situated at the point of structure change. The drawn-out parts of the baseoendopods of the female P5 are cleft medially and angled at the distal ends in both species. The most obvious differences between the two species are the relationship of length to width of the furcal rami, the total length of the furcal rami compared to the three last body somites, the articulated/non-articulated base of seta VII at the furcal rami, and the presence/absence of a seta at the syncoxa of the maxilliped. The new species presented here raise the number of valid members of the genus to 39.

The new deep-sea copepod species of the family Paramesochridae (Copepoda, Harpacticoida) presented here was collected during the scientific ANtarctic benthic DEEP-sea biodiversity cruise II (ANDEEP II) to the Weddell Abyssal Plain and western Weddell Sea and the CROZet natural iron bloom and EXport experiment (CROZEX cruise) to the Crozet Isles in the Indian Ocean. The new species has been allocated to the subgenus Wellsopsyllus within the genus Wellsopsyllus Kunz, 1981, based on the 1-segmented endopods and 3-segmented exopods of swimming legs 2–4. Furthermore, the new species shows a 1-segmented exopod of the antenna. Wellsopsyllus (W.) antarcticus sp. n. can be distinguished from its congeners by its small body size, the presence of two setae on the distal segment of the endopod of the first swimming leg, by the very small furcal rami, the extremely reduced endopods of second and third swimming legs, the reduced mandibular palp and maxillula, as well as by the size and armature of the fifth and sixth swimming legs in both sexes. Difficulties of the placement of the new species into a suitable genus show an insufficiency in the present family classification. In the future, a revision of the genus Wellsopsyllus is essential. With its presence in the western Weddell Sea and the Indian Ocean, the new species may have a wide distribution range. Furthermore, it is the first abyssal species of the genus Wellsopsyllus sampled outside of the Scotia Sea.

To examine the specific features of trench communities, spatial changes in the assemblages of harpacticoids were investigated at the family level around the Ryukyu Trench (the Ryukyu region) and Kuril Trench (the Kuril region). In the Ryukyu region, there were high average dissimilarities in the harpacticoid assemblages among the trench, trench slope and abyssal plain, indicating that the assemblage structures differ substantially between these topographic settings at the family level. Conversely, in the Kuril region, the average dissimilarities in harpacticoid assemblages between the trench and the trench slope and between the trench and the abyssal plain were lower than that between the slope and the abyssal plain. This result suggests that the hadal assemblage is a transition zone between the slope and the abyssal plain in this region. In addition, the analyses indicate that the composition of harpacticoid assemblages is influenced by the quantity of organic matter in the Ryukyu region, while sediment properties play a key role in the Kuril region. Comparisons of the assemblages between the two regions, however, revealed that the average dissimilarities between the trenches and between the abyssal plains were higher than that between the adjacent slopes. This result suggests that interchange among regions is difficult for deep-sea benthic animals, including harpacticoid copepods, likely due to the presence of physical barriers around trenches.

During the RV Polarstern ANT XXIV-2 cruise to the Southern Ocean and the Weddell Sea in 2007/2008, sediment samples were taken during and after a phytoplankton bloom at 52°S 0°E. The station, located at 2960 m water depth, was sampled for the first time at the beginning of December 2007 and revisited at the end of January 2008. Fresh phytodetritus originating from the phytoplankton bloom first observed in the water column had reached the sea floor by the time of the second visit. Absolute abundances of bacteria and most major meiofauna taxa did not change between the two sampling dates. In the copepods, the second most abundant meiofauna taxon after the nematodes, the enhanced input of organic material did not lead to an observable increase of reproductive effort. However, significantly higher relative abundances of meiofauna could be observed at the sediment surface after the remains of the phytoplankton bloom reached the sea floor. Vertical shifts in meiofauna distribution between December and January may be related to changing pore-water oxygen concentration, total sediment fatty acid content, and pigment profiles measured during our study. Higher oxygen consumption after the phytoplankton bloom may have resulted from an enhanced respiratory activity of the living benthic component, as neither meiofauna nor bacteria reacted with an increase in individual numbers to the food input from the water column. Based on our results, we infer that low temperatures and ecological strategies are the underlying factors for the delayed response of benthic deep-sea copepods, in terms of egg and larval production, to the modified environmental situation.

A large-scale database concerning benthic copepods from the Arctic, Baltic Sea, North Sea, British Isles, Adriatic Sea and Crete was compiled to assess species richness, biodiversity, communities, ecological range size and biogeographical patterns. The Adriatic showed the highest evenness and the most species-rich communities. Assemblages from the North Sea, British Isles, Baltic and Crete had a lower evenness. The British Isles were characterised by impoverished communities. The ecological specificity of copepod species showed two diverging trends: higher specificity of species in more diverse assemblages was observed in the Adriatic, North Sea and Baltic. A uniformly high species specificity disregarding sample diversity was found on Crete and in the British Isles. Benthic copepod communities showed distinct patterns that clearly fit the predefined geographical regions. Communities were distinguishable and β-diversity was found to be high around Europe, indicating a high species turnover on the scale of this investigation. The British Isles and the North Sea were found to be faunistic links to the Baltic and the Arctic.

Several specimens belonging to a new species of Apodopsyllus were collected during a study on the diversity of meiobenthic communities in the Gulf of Gabes, a Mediterranean shallow-water bay at the south-eastern coast of Tunisia in July 2005. The new species Apodopsyllus gabesensis n. sp. shares the characteristics of the genus such as the lack of endopods from P2 to P4 and the soft and slightly cuticularized body. Apodopsyllus gabesensis n. sp. belongs to the few known species of Apodopsyllus that are described to have comparably distinct patterns of dorsal and lateral cuticular plates and pores. Besides a typical combination of characters that clearly distinguishes the new species from its congeners, the new species shows the following unique single characters: female P5 with a hitherto unknown combination of shape of the exopodal part and shape and setation of the baseoendopodal lobe with two small stout spines; male P6 with a particular shape, and a distinct armature of the exopodal spines in P2–P4 in the male that are pinnate with very short spinules contrary to the female where spines are smooth. The genus Apodopsyllus contains 26 species with the inclusion of the new species.

Bradyatypica Boeck, 1873 is described from samples collected in the course of a colonisation experiment in Kongsfjorden, Spitsbergen (2003–2005). The male of B. typica, the type-species of the genus is described for the first time. B. typica can be distinguished from its congeners by its caudal rami (1.4 times longer than wide) and by its P5 (exopod longer than wide, inner terminal seta of exopod longest, inner seta of baseoendopod longer than outer one and surface seta rigid and curved). Variability within the species is rather small as only the length of some setae is slightly different. B. cladiofera Lang, 1965, B. congenera Sars, 1920, B. minutiseta Soyer, 1973 and B.pugiochaeta Arlt, 1983 are closely related to B. typica. Some details of the morphology, such as the body ornamentation and the longer hair-like pinnules on the spines of the swimming legs, are very difficult to observe even with maximum magnification. With certainty, B. typica is distributed near the Norwegian coast (Oslo Fjord to Trondheim Fjord), the Swedish coast (Skagerak to Oresund), around Spitsbergen and around the polar islands north of Grinnelland (Canadian Arctic Archipelago near Baffin Bay). Records of B. typica from the Kara Sea (near Novaya Zemlya), near Franz Joseph Land, Iceland, Greenland, the British Isles and from deep waters of the North Sea have to be confirmed.

Multicorer samples for meiofaunal study were obtained within the framework of the international project CeDAMar, at 21 stations occupied during the DIVA and ANDEEP campaigns (2000, 2002 and 2005) to the southern Atlantic Ocean (Guinea, Angola and Cape Basins) and the Southern Ocean (Weddell and Scotia Seas), respectively. A total of 311 adult Paramesochridae Lang, 1944 (Copepoda, Harpacticoida) was extracted from 437 cores obtained during 83 deployments of the corer at depths between 1107 and 5655 m. All specimens were determined to species based on morphological characteristics. They belonged to 19 species and four genera (Kliopsyllus Kunz, 1962, Leptopsyllus T. Scott, 1894, Paramesochra T. Scott, 1892 and Scottopsyllus Kunz, 1962). Eleven species were restricted to single regions,whereas the others showed a much wider distribution. For example, Kliopsyllus andeep Veit-Köhler, 2004 and Kliopsyllus diva Veit-Köhler, 2005, were both collected from Guinea, Angola and Weddell Abyssal Plains,and Kliopsyllus schminkei Veit-Köhler & Drewes, 2009 occurred in the three West-African basins. This study provides a first insight into the large-scale biogeography of deep-sea harpacticoids, represented by the Paramesochridae, and indicates that distribution ranges, at least in this family, may extend across South Atlanticand Southern Ocean Abyssal Plains.

This study presents data of the first investigation on benthic harpacticoid copepods in Potter Cove, King George Island, Antarctica (62°14’S, 58°40’W) with special emphasis on spatial distribution and relation to environmental factors. In addition to the individual numbers that are normally given, the biovolume of the meiobenthic copepods was measured. It showed great variety due to changes in abundance and habitat preferences of the different species along the two studied transects in the inner cove and at the cove entrance. The distribution of the two species Pseudotachidius jubanyensis and Scottopsyllus (S.) praecipuus was studied in detail; their body volumes are given for developmental stages and adults, and their importance for the total biovolume at the different stations is discussed. Statistical analyses (Spearman rank, canonical correspondence analysis) indicate that the biovolume of harpacticoid copepods was related more to total organic matter than to the carbon:nitrogen ratio and chloroplastic equivalents or even grain size and depth. While P. jubanyensis was strongly connected to depth and to a lesser extent to small grain sizes, S. (S.) praecipuus showed a preference for sites with low chloroplastic equivalent values, but neither of them was related to total organic matter. El presente estudio facilita los primeros datos sobre la distribución espacial de los copépodos harpacticoídeos bentónicos en la Caleta Potter, Isla Rey Jorge, Antártida (62°14’S, 58°40’W) y su relación con factores ambientales. Además del cálculo de abundancias se midió el biovolumen de los copépodos del meiobentos. Se detectó una variabilidad bastante elevada del biovolumen debido a las diferentes preferencias ecológicas de las especies a lo largo de los dos transectos muestreados, uno en la entrada de la cala y otro en su interior. La distribución de dos de las espécies encontradas, Pseudotachidius jubanyensis y Scottopsyllus (S.) praecipuus, fué estudiada en detalle. Se presentan datos del biovolumen de los diferentes estadios ontogenéticos y de los adultos de estas dos especies y se discute su importancia para el biovolumen total en las diferentes estaciones muestreadas. Análisis estadísticos (Spearman rank, análisis canónico de correspondencias) indican que el biovolumen de los copépodos harpacticoídeos está mejor correlacionado con el contenido orgánico total que con la relación carbono:nitrógeno y equivalentes de pigmentos cloroplásticos o incluso con parámetros granulométricos y profundidad. P. jubanyensis parece estar relacionado con la profundidad y, en menor medida, con sedimento de grano fino, mientras que S. (S.) praecipuus mostró preferencia por estaciónes con valores bajos de equivalentes de pigmentos cloroplásticos, pero ninguna de las especies está relacionada con el contenido total de materia orgánica.

The international scientific deep-sea cruise ANDEEP-2 (ANT XIX/4) to the Scotia Arc and the northern Weddell Sea in 2002 revealed a new species of the family Paramesochridae (Copepoda: Harpacticoida). Kliopsyllus andeep sp. n. can be distinguished from its congeners by characteristics such as a two-segmented endopod on the fourth leg and an additional seta on the endopod of the third leg. The most striking feature is its strong, flexed, chitinous thorns on the telson. Only three species in the family have such appendages, all of them interstitial, shallow-water species. Because the new species lacks the strong abdominal muscle observed by Kunz in Kliopsyllus furcavaricatus Kunz, 1974, it cannot spread its furcal rami using the thorns on the telson as antagonists the way the shallow-water species does. The furcal-rami spreading system, which is an adaptation to interstitial living, for K. andeep sp. n. is irrelevant, because the species has been collected from muddy sediments. Therefore, the abdominal muscle might have been lost during the species’ evolution.

Meiofauna standing stocks and community structure are reported for the first time for abyssal soft-sediment samples in Antarctic waters. At seven stations within a depth range of 2274–5194 m a total of 128 sediment cores were retrieved with a multiple corer (MUC) on board of the R.V. Polarstern during the ANDEEP-1 cruise (ANT XIX/3). The metazoan meiofauna (defined by a lower size limit of 40 μm) was identified and counted, and one core per station was preserved for CPE, C/N, TOM and grain size analyses. Meiofauna densities are in the range of 2731 Ind./10 cm2 at 2290 m depth and 75 Ind./10 cm2 at 3597 m depth, with nematodes being the dominant group at all stations. Nematodes account for 84–94% followed by copepods with 2–8% of the total meiofauna. Other frequent taxa found at each station are kinorhynchs, loriciferans, tantulocarids, ostracods and tardigrades. There is a general tendency of decreasing abundances of metazoan meiofauna with increasing depth, but not all higher level taxa displayed this pattern. In addition, a tendency of decreasing higher taxon density with increasing depth was observed. Standing stocks are higher than the average found at similar depths in other oceans.

Marine free-living nematode communities were studied at similar depths (similar to 500 m) at two sides of the Antarctic Peninsula, characterised by different environmental and oceanographic conditions. At the Weddell Sea side, benthic communities are influenced by cold deep-water formation and seasonal sea-ice conditions, whereas the Drake Passage side experiences milder oceanic conditions and strong dynamics of the Antarctic Circumpolar Current. This resulted in different surface primary productivity, which contrasted with observed benthic pigment patterns and varied according to the area studied: chlorophyll a concentrations (as a proxy for primary production) were high in the Weddell Sea sediments, but low in the surface waters above; this pattern was reversed in the Drake Passage. Differences between areas were largely mirrored by the nematode communities: nematode densities peaked in Weddell stations and showed deeper vertical occurrence in the sediment, associated with deeper penetration of chlorophyll a and indicative of a strong benthopelagic coupling. Generic composition showed some similarities across both areas, though differences in the relative contribution of certain genera were noted, together with distinct community shifts with depth in the sediment at all locations.

A new species of the genusPseudotachidius T.Scott, 1898 from Potter Cove on King George Island, South Shetland Islands, Antarctica is described. It is confirmed that the genusPseudotachidius can be separated into two groups: thesimilis- and thecoronatus-group due to the shape of the PI, the rostral setation, a modified Mxp and the female P5.Pseudotachidius jubanyensis sp. nov. is the first representative of the genus to be found in such shallow waters (20 m depth). The characterization of the site as a low energy soft bottom habitat gives rise to the assumption that in Antarctic shallow waters members of the mainly deep-sea genusPseudotachidius encounter suitable conditions. Despite its low individual numbersPseudotachidius jubanyensis nearly outranges all other harpacticoid copepods regarding biovolume per sediment surface unit because of its large body size. Therefore it tends to play an important role in the benthic meiofauna community.

Due to their high abundance and large body size sponges have a central position in Antarctic zoobenthos, where they form the most extensive sponge grounds of the world. Though research on Antarctic benthos communities is quite established, research on sponge-associated infauna communities is scarce. We analyzed associated infauna of fifteen individuals of the sponge species Mycale (Oxymycale) acerata Kirkpatrick, 1907 (Demospongiae: Mycalina), Rossella antarctica Carter, 1872 and R. racovitzae Topsent, 1901 (both Hexactinellida: Lyssacinosida). Samples were collected from the deep Ekstrom Shelf at 602 m in the South-Eastern Weddell Sea, Antarctica, during the ANT XXIV-2 (SYSTCO I) expedition of RV Polarstern. The number of species, α- and β-diversity and the significantly different species composition of infauna communities related to sponge species were calculated, the latter via cluster analysis. The sponge-associated infauna consisted of five phyla: Foraminifera, Nematoda, Polychaeta, Mollusca and Arthropoda. In total 11,463 infaunal specimens were extracted and we found at least 76 associated species. Highest values of α-diversity were calculated for a sample of R. antarctica with a Shannon-Index of 1.84 and Simpson-Index of 0.72 respectively. Our results of the cluster-analysis show significant differences between infauna communities and a unique species composition for single sponge species. Polychaetes of the genus Syllis Lamarck, 1818 were numerous in M. acerata and genera like Pionosyllis Malmgren, 1867 and Cirratulus Lamarck, 1801 were numerous in R. antarctica. Individuals of the amphipod species Seba cf. dubia Schellenberg, 1926 were often found in R. antarctica and R. racovitzae while Colomastix fissilingua Schellenberg, 1926 was frequent in samples of M. acerata. Molluscs were present in M. acerata and R. antarctica but absent in R. racovitzae.

23 pages; International audience; In the Southern Ocean, that is areas south of the Polar Front, long-term oceanographic cooling, geographic separation, development of isolating current and wind systems, tectonic drift and fluctuation of ice sheets amongst others have resulted in a highly endemic benthic fauna, which is generally adapted to the long-lasting, relatively stable environmental conditions. The Southern Ocean benthic ecosystem has been subject to minimal direct anthropogenic impact (compared to elsewhere) and thus presents unique opportunities to study biodiversity and its responses to environmental change. Since the beginning of the century, research under the Census of Marine Life and International Polar Year initiatives, as well as Scientific Committee of Antarctic Research biology programmes, have considerably advanced our understanding of the Southern Ocean benthos. In this paper, we evaluate recent progress in Southern Ocean benthic research and identify priorities for future research. Intense efforts to sample and describe the benthic fauna, coupled with coordination of information in global databases, have greatly enhanced understanding of the biodiversity and biogeography of the region. Some habitats, such as chemosynthetic systems, have been sampled for the first time, while application of new technologies and methods are yielding new insights into ecosystem structure and function. These advances have also highlighted important research gaps, notably the likely consequences of climate change. In a time of potentially pivotal environmental change, one of the greatest challenges is to balance conservation with increasing demands on the Southern Ocean's natural resources and services. In this context, the characterization of Southern Ocean biodiversity is an urgent priority requiring timely and accurate species identifications, application of standardized sampling and reporting procedures, as well as cooperation between disciplines and nations.

This study describes and combines structural and functional aspects of deep-sea nematode assemblages from the Atlantic sector of the Southern Ocean. Samples were collected at six stations along the Prime Meridian (49–70°S), including a repeated sampling after one and a half months interval at the Polar Front (52°S), where meanwhile a seasonal phytoplankton bloom had settled. The aim was to gain insight in the latitudinal and temporal variability in nematode community structure and diet based on the generic composition and bulk fatty acid composition of the community, respectively. The results show that nematode assemblages along the transect differed relatively little and that they were all highly comparable to slope and abyssal communities elsewhere in the world in terms of nematode standing stock, diversity and composition. Nematode community composition was only weakly correlated with the community fatty acid composition, indicating that simply the occurrence of distinct genera or the proportion of nematode feeding types based on mouth morphology, cannot explain the variance in FA compositions of the communities. Moreover, the generally low FA content of nematodes suggests that they do not accumulate lipids for energy storage and that they may feed throughout the year on constantly available food sources. A year-round foraging activity could also explain the recorded lack of food uptake as a short-term response to the recently settled phytodetritus at the revisited Polar Front station. Nevertheless, the higher relative abundance of nematodes in the top centimeter layer of the sediment and the occurrence of the genus Leptolaimus only after phytodetritus had settled at the seafloor, suggests the recording of an early stage in a delayed response to the seasonal event.

Sediment samples were collected from the deep sea adjacent to the State of Sergipe (Northeastern Brazil) within the framework of the Sergipe Continental Slope Environmental Characterization Project (coordinated by PETROBRAS, the Brazilian Petroleum Company S/A). These revealed a new species of the family Paramesochridae (Copepoda, Harpacticoida). Kliopsyllus minor sp. nov. is the smallest species discovered in this genus, with a body length of 0.19 mm in the adult male. Furthermore, it is one of the three Kliopsyllus species registered from the deep sea so far. In almost all Kliopsyllus species, the endopod of P4 is one-segmented. Only three species, i.e. Kliopsyllus andeep Veit-Köhler, 2004 from the abyssal Weddell Sea, a new species by Veit-Köhler and Thistle from the San Diego Trough (deep Pacific Ocean) and the new species presented here, show a two-segmented endopod in the P4. Kliopsyllus andeep is distinguished by the presence of strong, chitinous processes at the telson, and additional setae at the endopods of P3 and P4. The new Pacific species and the new species from Brazil can be distinguished by the shape of the segments of the swimming legs and detailed characteristics of their setae and spines.

ARTICLE I NFO An in situ experiment on metazoan meiofauna colonisation and succession was carried out at Brandal (78°56.88'N, 11°51.63'E), situated in arctic glacial Kongsfjorden (Spitsbergen). 28 soft sediment containers were deployed at a depth of 20 m and sampled after a one-, two- and three-year immersion period. The main taxonomic groups, abundance of colonising meiofauna and sediment parameters are described and compared. Meiofauna communities at Brandal show the highest densities reported for inner Kongsfjorden to date. While the samples from the three experimental periods and the ambient sediments did not differ in total individual numbers, the treatments showed marked differences in community structure as ascertained by ANOSIM based on Bray Curtis and cosine similarity. An extended three-year period was required until the community stage comparable to ambient sediments was reached. This leads to the assumption that long recovery and colonisation times can be expected for polar shallow water meiofauna.