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. This suggests that vertical nets are more efficient for biomass assessments, and we report these values here. We further compared day and night samples from the same site and found that biomass estimates differed only in the epi- and mesopelagic strata, while estimates from the bathypelagic strata and the total water column were independent of time of day. Maximal shrimp standing stocks occurred in the upper bathypelagic (52–54% of total biomass) and in the mesopelagic (42–43%). We assessed shrimp biomass in three major regions of the Atlantic between 40°N and 40°S, and the first-order extrapolation of these data suggests that the global low-latitude deep-pelagic shrimp biomass (1700 million tons) may lie within the range reported for mesopelagic fishes (estimations between 1000 and 15000 million tons). These data, along with previous fish-biomass estimates, call for the reassessment of the quantity and distribution of nektonic carbon in the deep ocean

Global diversity and phylogeny of pelagic shrimps of the former genera <i>Sergestes </i>and <i>Sergia </i>(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. There is no support for the genera Sergia and Sergestes as they have been defined until now. We define and diagnose eight genera of the former genus Sergia (Sergia and new genera Gardinerosergia, Phorcosergia, Prehensilosergia, Robustosergia, Scintillosergia, Challengerosergia, and Lucensosergia) and seven genera of the former genus Sergestes (Sergestes, Deosergestes, Eusergestes, Allosergestes, Parasergestes, Neosergestes, and a new genus Cornutosergestes). An identification key is presented for all genera of the family Sergestidae. The phylogeny of Sergestidae is mainly based on three categories of characters related to: (1) general decapod morphology, (2) male copulatory organs, and (3) photophores. Only simultaneous use of all three character types resulted in a resolved tree with minimal Bootstrap support 75 for each clade. Most genera are interzonal mesopelagic migrants, some are benthopelagic (Scintillosergia, Lucensosergia), bathypelagic (Sergia), or epipelagic (Cornutosergestes). Within each of meso- and benthopelagic genera there is one species with panoceanic distribution, while most species ranges are restricted to a single ocean. The genera demonstrate two different strategies expressed both in morphology and behavior: protective (Eusergestes, Sergestes, Cornutosergestes, Prehensilosergia, Scintillosergia, Lucensosergia, Challengerosergia, Gardinerosergia, Robustosergia, Phorcosergia, Sergia) and offensive (Neosergestes, Parasergestes, Allosergestes, Deosergestes)

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. We detected very diverse eukaryotes belonging to Alveolata, Fungi, Amoebozoa, Viridiplantae, Metazoa, Rhizaria, Heterokonta, and Telonemia. Different alveolates (dinoflagellates and Marine Alveolate Groups I and II species) were the most abundant and diverse in gene libraries from water and sea ice, representing 80% of the total number of clones and operational taxonomic units. Only contaminants and/or species from continental ecosystems were detected in snow, suggesting wind- and animal- or human-mediated cosmopolitan dispersal of some taxa. By contrast, sea ice and seawater samples harbored a larger and more similar inter-sample protist diversity as compared with snow. The North Pole was found to harbor distinctive eukaryotic communities along the vertical gradient with an unparalleled diversity of core dinoflagellates, largely dominant in libraries from the water column, as compared to other oceanic locations. In contrast, phototrophic organisms typical of Arctic sea ice and plankton, such as diatoms and prasinophytes, were very rare in our samples. This was most likely due to a decrease of their populations after several months of polar night darkness and to the presence of rich populations of diverse grazers. Whereas strict phototrophs were scarce, we identified a variety of likely mixotrophic taxa, which supports the idea that mixotrophy may be important for the survival of diverse protists through the long polar night

The Averaged EMGs Recorded from the Arm Muscles During Bimanual “Rowing” Movements

The main purpose was to analyze quantitatively the the average surface EMGs of the muscles that function around the elbow and shoulder joints of both arms in similar bimanual ‘rowing’ movements, which were produced under identical elastic loads applied to the levers (‘oars’). The muscles of PM group (‘pulling’ muscles: elbow flexors, shoulder extensors) generated noticeable velocity-dependent dynamic EMG components during the pulling and returning phases of movement and supported a steady-state activity during the hold phase. The muscles of RM group (‘returning’ muscles: elbow extensors, shoulder flexors) co-contracted with PM group during the movement phases and decreased activity during the hold phase. The dynamic components of the EMGs strongly depended on the velocity factor in both muscle groups, whereas the side and load factors and combinations of various factors acted only in PM group muscles. Various subjects demonstrated diverse patterns of activity redistribution among muscles. We assume that central commands to the same muscles in two arms may be essentially different during execution of similar movement programs. Extent of the diversity in the EMG patterns of such muscles may reflect the subject’s skilling in motor performance; on the other hand, the diversity can reflect redistribution of activity between synergic muscles, thus providing a mechanism directed against development of the muscle fatigue

C60 fullerenes diminish muscle fatigue in rats comparable to N-acetylcysteine or β-Alanine

The aim of this study is to detect the effects of C60 fullerenes, which possess pronounced antioxidant properties, in comparison with the actions of the known exogenous antioxidants N-acetylcysteine (NAC) and β-Alanine in terms of exercise tolerance and contractile property changes of the m. triceps surae (TS) during development of the muscle fatigue in rats. The electrical stimulation of the TS muscle during four 30 min series in control rats led to total reduction of the muscle contraction force. Furthermore, the effects of prior intraperitoneal (i.p.) or oral C60FAS application and preliminary i.p. injection of NAC or β-Alanine on muscle contraction force under fatigue development conditions is studied. In contrast to control rats, animals with C60FAS, NAC, or β-Alanine administration could maintain a constant level of muscle effort over five stimulation series. The accumulation of secondary products and changes in antioxidant levels in the muscle tissues were also determined after the fatigue tests. The increased levels of lactic acid, thiobarbituric acid reactive substances and H2O2 after stimulation were statistically significant with respect to intact muscles. In the working muscle, there was a significant (p < 0.05) increase in the activity of endogenous antioxidants: reduced glutathione, catalase, glutathione peroxidase, and superoxide dismutase. Treated animal groups showed a decrease in endogenous antioxidant activity relative to the fatigue-induced animals (P < 0.05). Oral C60FAS administration clearly demonstrated an action on skeletal muscle fatigue development similar to the effects of i.p. injections of the exogenous antioxidants NAC or β-Alanine. This creates opportunities to oral use of C60FAS as a potential therapeutic agent. Due to the membranotropic activity of C60 fullerenes, non-toxic C60FAS has a more pronounced effect on the prooxidant-antioxidant homeostasis of muscle tissues in rats

SNAGA, TEORIJA I PRAKSA (Kraft, Theorie und Praxis)

We have developed a global biogeographic classification of the mesopelagic zone to reflect the regional scales over which the ocean interior varies in terms of biodiversity and function. An integrated approach was necessary, as global gaps in information and variable sampling methods preclude strictly statistical approaches. A panel combining expertise in oceanography, geospatial mapping, and deep-sea biology convened to collate expert opinion on the distributional patterns of pelagic fauna relative to environmental proxies (temperature, salinity, and dissolved oxygen at mesopelagic depths). An iterative Delphi Method integrating additional biological and physical data was used to classify biogeographic ecoregions and to identify the location of ecoregion boundaries or inter-regions gradients. We define 33 global mesopelagic ecoregions. Of these, 20 are oceanic while 13 are ‘distant neritic.’ While each is driven by a complex of controlling factors, the putative primary driver of each ecoregion was identified. While work remains to be done to produce a comprehensive and robust mesopelagic biogeography (i.e., reflecting temporal variation), we believe that the classification set forth in this study will prove to be a useful and timely input to policy planning and management for conservation of deep-pelagic marine resources. In particular, it gives an indication of the spatial scale at which faunal communities are expected to be broadly similar in composition, and hence can inform application of ecosystem-based management approaches, marine spatial planning and the distribution and spacing of networks of representative protected areas

A New Shrimp Genus (Crustacea: Decapoda) from the Deep Atlantic and an Unusual Cleaning Mechanism of Pelagic Decapods

The deep sea is the largest biome on Earth and hosts the majority of as yet undescribed species; description of these may trigger a new mindset about evolution and function of characters. We describe and diagnose a new genus and species Sclerodora crosnieri sp. nov. belonging to the superfamily Oplophoroidea. We examined and coded 81 characters for morphological analyses and used four gene markers for molecular analyses involving the new taxon and representatives of all other genera of Oplophoroidea. Retrieved morphological and molecular trees were similar and suggested that the new genus is a sister group to Hymenodora and both form a clade sister to the rest of Acanthephyridae. We provide an amended key to all genera of Oplophoroidea. We found an unusual chelate structure on the dactyl of the fifth pereopod, tested and confirmed a hypothesis that this structure is common for the whole family Acanthephyridae. We suggest that this derived structure is linked to an active cleaning of branchia—a function associated with chelipeds in some other carid shrimps. Convergent chelate structures are likely efficient for cleaning branchia, whichever appendage is adapted for these functions. In Oplophoridae (sister to Acanthephyridae), cleaning function is carried out by well-developed epipods

Appendix 6

Appendix