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The Gulf of Gabès, located on the south-east Tunisian coast, is an important maritime area, with great influence on the local economy and human welfare. The aim of the current study was to assess the response of meiobenthic copepod populations from this gulf to anthropogenic disturbances. Nine sampling sites, situated along the shores of the gulf were surveyed seasonally from winter of 2004 to autumn of 2005. Interestingly, this biotope has one of the highest semi-diurnal tides in the Mediterranean Sea. Despite the fact that the data being presented here are not that new, such a high maximum amplitude of tides reaching 2 m makes any information available on animals with diurnal dispersal cycles such as copepods extremely precious. Furthermore, the lack of knowledge on these crustaceans is obvious and lags behind that of numerous other meiobenthic taxa and planktonic calanoids. Actually, most publications do not reach the species level and are limited to determining densities. This is mainly due to the modest size of harpacticoids, and the lack of qualified taxonomic experts and global taxonomic databases. Sediment samples were analyzed for fluorine, carbohydrates and trace metals (i.e., Fe, Zn and Cd) content. A pollution index, based on the eigenvalues of the main ordination axis of a Principal Component Analysis, was applied. The highest values of chemicals were detected at the sites situated near an industrial complex, along with significant variations among seasons. The copepod community comprised 38 species, including five species new to science. Species richness, density and biomass of copepod communities varied among sites and seasons. These community-based indices were also analyzed separately for each season with conditional autoregressive models, revealing a significant negative response with the level of pollution. However, the results of partial Mantel tests showed positive correlations between species richness and pollution level, after controlling for the effect of geographic proximity in-between pairs of sites (winter: r = 0.927, p < 0.0001; spring: r = 0.935, p < 0.0001; summer: r = 0.918, p < 0.0001; autumn: r = 0.937, p < 0.0001). The overall pattern was that nearby sites were characterized by similar pollution levels and inhabited by similar species of copepods. Moreover, the copepod communities were significantly influenced by pollutants, mainly by trace metals. The results of the current survey emphasize the usefulness of meiobenthic copepods in biomonitoring programs not only for the gulf of Gabès, but also for other coastal areas from the Mediterranean Sea region.

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.

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.

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.

A new harpacticoid copepod species was found during a year round plankton survey in a shallow Antarctic bay. Both the dominant Calanoida and Cyclopoida and the often neglected Harpacticoida, their abundances in relation to sea-ice formation and decline in presence of Euphausia superba are regarded, in this study. Alteutha potter sp. n. (Peltidiidae) was collected in Potter Cove, King George Island, Antarctica. While its geographical region occurrence and planktonic life style are comparable to many of its congeners, morphological characters such as shape and setation of the maxilliped and the almost complete fusion of the baseoendopod and the exopod of the fifth leg in the female are described for the first time for this genus. Morphological peculiarities such as the lack, the deformation or fusion of setae on only one body side have been detected in several specimens. This copepod species is obviously sea-ice related. Its abundances in the plankton reached a maximum under the winter sea-ice. The year round population structure did not show very high variability whereas ovigerous females mostly occurred in spring and summer. Assuming different possible ecological strategies and environmental temperatures generation times between 46 and 77 days are calculated for A. potter sp. n. Fil: Veit-Köhler, Gritta. Senckenberg Gesellschaft Für Naturforschung; Alemania Fil: Fuentes, Verónica Lorena. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria; Argentina. Universidad de Buenos Aires; Argentina. Alfred-wegener-institut Helmholtz-zentrum Für Polar- Und Meeresforschung

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.

Two of the sites sampled during the DIVA-1 cruise (Meteor 48/1) to the Angola Basin in 2000 have been studied intensively in order to highlight the diversity of meiofauna in this deep-sea region. This work contributes to the final aim to describe the species of the community of harpacticoid copepods in the Angola Basin and adds a new member to the few hitherto known deep-sea Paramesochridae. The new species belongs to the genus Kliopsyllus, until now only reported from beaches, the intertidal and shallow waters and thus thought to be representing a mainly interstitial group. Furthermore, Kliopsyllus diva sp. n. is the dominating paramesochrid copepod at the two studied sites with depths of more than 5400 m. Among other features, K. diva sp. n. is unique in the armature of its fourth leg, the presence of hedgehog-like arranged spinules on the exopod of the fifth leg and the relation of length and width of its furcal rami.

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.

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.

A new species of Kliopsyllus (Paramesochridae) has been collected with a multicorer from the abyssal Angola Basin in 2000 (on the DIVA-1 cruise, RV Meteor 48/1). Kliopsyllus schminkei sp. n. is the second most abundant Kliopsyllus- species in the Angola Basin and raises the number of valid members of the genus to 33. The new species is placed in the genus Kliopsyllus because of its typical segmentation and the setation of the swimming legs. K. schminkei sp. n. is unique within the genus and can be distinguished from the other species by a large apical pore on the P5 baseoendopodal lobes of the male, a length:width ratio of the furcal rami of 9 to 10:1 in both sexes, and an exceptional ratio of the length of the furcal rami to the whole body size of one fourth in the female and one fifth in the male. The new species is one of the four deep-sea Kliopsyllus-species described until now.

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.

A methodology for comparing repeatedly sampled multicorer stations as to significant differences in alpha diversity of selected cores is presented. This is demonstrated for Harpacticoida of the Angola Basin which were sampled during the DIVA-1 campaign of RV “Meteor” in the year 2000 (M48/1). Two replicatedly sampled multicorer stations were compared as to their species-level alpha diversity values of all adult Harpacticoida in single cores. This was done by a newly developed procedure: based on a rank-ordered alpha diversity matrix, using each a species richness, evenness, and dominance diversity index, a minimum spanning tree test (MST-test) was performed to test for significant diversity differences between the replicates of stations 325 (depth: 5448 m) and 346 (depth: 5389 m). The Canberra Metric was used as a measure of dissimilarity between multicorer deployments. With this procedure, any choice of combination of diversity indices can be made, according to the desired emphasis on certain aspects of diversity. This freedom of choice, together with the possibilities to test for significant diversity differences and to visualize this test, are desirable features of the presented procedure for diversity comparisons. Testing for diversity differences may be useful in the context of conservational purposes when politicians need clear statements from scientists. Due to sufficient replicates, for the first time a significant diversity difference between two abyssal (>2000 m depth) multicorer stations was detectable. Station 346 (eight replicates) was significantly more diverse in harpacticoid species than station 325 (seven replicates). Regional-scale differences in food availability are assumed to be of importance for the different patterns of diversity at stations 325 and 346. The slope of the line of regression in a species/individuals plot on single-core level was not far from 1 ( R 2 = 0.990 ; y = 0.877 x ) , indicating that most species were represented by singletons and the rest only by very few specimens. The data supported scale-dependent differences of harpacticoid diversity in the Angola Basin. Local-scale (between replicates) differences in harpacticoid within-core species diversity were lower than regional-scale (between stations) differences. At least 134 species of Harpacticoida were found at the two stations, of which the subgroups of Pseudotachidiidae, Argestidae, Ameiridae, and Ectinosomatidae turned out to be richest in species and individuals.