Revision of the 'Acanthephyra purpurea' species complex (Crustacea: Decapoda), with an emphasis on species diversification in the Atlantic.

We inventoried all nine species of the 'Acanthephyra purpurea' complex, one of the most abundant and cosmopolitan group of mesopelagic shrimps. We used 119 specimens at hand and genetic data for 124 specimens from GenBank and BOLD. Phylogenetic analysis of four genes (COI, 16S, NaK, and enolase) showed that the 'Acanthephyra purpurea' complex is polyphyletic and encompasses two species groups, 'A.

Precision of mesoplankton sampling: A case study based on three net series in the South Atlantic and in the Black Sea.

Mesoplankton is a key element of pelagic communities representing the largest biome on the planet. Many concepts in marine and freshwater biology are based on quantitative estimates of mesoplankton abundance, whereas precision of mesoplankton sampling remains underexplored and may depend on various factors. We analyzed ten contiguous daytime epipelagic samples in the Black Sea and 13 nighttime mesopelagic samples in the South Atlantic.

Biogeography of the Southern Ocean: environmental factors driving mesoplankton distribution South of Africa.

Spatial distribution of zooplankton communities depends on numerous factors, especially temperature and salinity conditions (hydrological factor), sampled depth, chlorophyll concentration, and diel cycle. We analyzed and compared the impact of these factors on mesoplankton abundance, biodiversity, quantitative structure based on proportion of taxa and qualitative structure based on presence/absence of taxa in the Southern Ocean. Samples (43 stations, three vertical strata sampled at each station, 163 taxa identified) were collected with a Juday net along the SR02 transect in December 2009.

The Southern Polar Front as a key to mesoplankton migratory behavior.

Diel and seasonal vertical migrations of zooplankton represent a widespread phenomenon occurring in marine and freshwater environments. Diel migrations are panoceanic, while seasonal migrations usually occur in temperate and polar areas. This paper describes differences in the diel and seasonal vertical migrations in the Drake Passage north and south of the Polar Front (PF).

Zooplankton communities in the Drake Passage through environmental boundaries: a snapshot of 2010, early spring.

Background: Spatial distribution of zooplankton communities influenced by various environmental factors is always important for understanding pelagic ecosystems. The area of the Drake Passage (Southern Ocean) is of particular interest owing to the high spatial and temporal variability of hydrological parameters affecting marine fauna. This study provides a survey of zooplankton composition and spatial distribution along a transect in the Drake Passage sampled during the 31th Cruise of RV "" in November, 2010.

Long-term studies reveal major environmental factors driving zooplankton dynamics and periodicities in the Black Sea coastal zooplankton.

Background: The development and management of shelf-sea ecosystems require a holistic understanding of the factors that influence the zooplankton structure and ecosystem functions. The Black Sea is an example of such areas influenced by eutrophication, overfishing, climate variability, invasions of the ctenophores followed by . Thus, there is a set of principal factors which may influence and explain periodicities in the Black Sea ecosystem.

Assessing Deep-Pelagic Shrimp Biomass to 3000 m in The Atlantic Ocean and Ramifications of Upscaled Global Biomass.

We assess the biomass of deep-pelagic shrimps in the Atlantic Ocean using data collected between 40°N and 40°S. Forty-eight stations were sampled in discrete-depth fashion, including epi- (0-200 m), meso- (200-800/1000 m), upper bathy- (800/1000-1500 m), and lower bathypelagic (1500-3000 m) strata. We compared samples collected from the same area on the same night using obliquely towed trawls and large vertically towed nets and found that shrimp catches from the latter were significantly higher.

A phylogenetic study of krill (Crustacea: Euphausiacea) reveals new taxa and co-evolution of morphological characters.

The first comprehensive phylogenetic study of Euphausiacea (all 86 valid species) is presented. It is based on four molecular markers and 168 morphological characters (including 58 characters of the petasma). Phylogenetic analyses support the monophyly and robustness of the families Bentheuphausidae and Euphausiidae and reveal three major clades for which we erect three new subfamilies: Thysanopodinae, Euphausiinae and Nematoscelinae.

The genus (Benthesicymidae: Decapoda): morphology of copulatory characters, phylogeny and coevolution of genital structures.

Species within differ from each other largely only in male (petasma) and female (thelycum) copulatory characters, which were restudied in scanning electron microscopy and used as a basis for phylogenetic analyses. Twenty-six petasma characters and 49 thelycum characters were identified. All 16 recognized species of and (outgroup) were included as terminals.

Phylogeny and New Classification of Hydrothermal Vent and Seep Shrimps of the Family Alvinocarididae (Decapoda).

The paper addresses the phylogeny and classification of the hydrothermal vent shrimp family Alvinocarididae. Two morphological cladistic analyses were carried out, which use all 31 recognized species of Alvinocarididae as terminal taxa. As outgroups, two species were included, both representing major caridean clades: Acanthephyra purpurea (Acanthephyridae) and Alpheus echiurophilus (Alpheidae).

Global diversity and phylogeny of pelagic shrimps of the former genera Sergestes and Sergia (Crustacea, Dendrobranchiata, Sergestidae), with definition of eight new genera.

We revise the global diversity of the former genera Sergia and Sergestes which include 71 valid species. The revision is based on examination of more than 37,000 specimens from collections in the Natural History Museum of Denmark and the Museum of Natural History, Paris. We used 72 morphological characters (61 binary, 11 multistate) and Sicyonella antennata as an outgroup for cladistic analysis.

Composition and dynamics of the Black Sea benthopelagic plankton and its contribution to the near-shore plankton communities.

At a shallow (7 m) near-shore sampling site in the Black Sea we analyzed composition, abundance, and biomass of benthopelagic organisms and the contribution these animals make to the total plankton. The site was monitored across several years (1996-2001; 2006-2007) whilst for 1999-2000 the seasonal variations were analysed. A total of 321 samples from Golubaja Bay near Novorossiysk (44°34'31.

Diversity and vertical distribution of microbial eukaryotes in the snow, sea ice and seawater near the north pole at the end of the polar night.

Our knowledge about the microorganisms living in the high Arctic Ocean is still rudimentary compared to other oceans mostly because of logistical challenges imposed by its inhospitable climate and the presence of a multi-year ice cap. We have used 18S rRNA gene libraries to study the diversity of microbial eukaryotes in the upper part of the water column (0-170 m depth), the sea ice (0-1.5 m depth) and the overlying snow from samples collected in the vicinity of the North Pole (N88°35', E015°59) at the very end of the long polar night.

Pan-oceanic distribution of new highly diverse clades of deep-sea diplonemids.

Molecular rRNA gene surveys reveal a considerable diversity of microbial eukaryotes in different environments. Even within a single clade, the number of distinct phylotypes retrieved often goes beyond previous expectations. Here, we have used specific 18S rRNA PCR primers to investigate the diversity of diplonemids, a poorly known group of flagellates with only a few described species.

Eukaryotic diversity associated with carbonates and fluid-seawater interface in Lost City hydrothermal field.

Lost City is a unique off-axis hydrothermal vent field characterized by highly alkaline and relatively low-temperature fluids that harbours huge carbonate chimneys. We have carried out a molecular survey based on 18S rDNA sequences of the eukaryotic communities associated with fluid-seawater interfaces and with carbonates from venting areas and the chimney wall. Our study reveals a variety of lineages belonging to eight major taxa: Metazoa, Fungi, Heterokonta (Stramenopiles), Alveolata, Radiolaria, Cercozoa, Heterolobosea and Euglenozoa.