Mesozooplankton structure in Dolgaya Bay (Barents Sea)

The community structure of mesozooplankton was investigated in Dolgaya Bay (southern Barents Sea), a subarctic fjord, using a Juday net (0.168-mm mesh size) in July, 2008. A total of 39 species and higher taxa were found. Average abundance, biomass and diversity (±standard error) were 153,403 ± 15,855 ind m⁻², 570 ± 61 mg dry mass m⁻², and 2.25 ± 0.09, respectively. Copepods were the most numerous species. The mesozooplankton communities were dominated by omnivores (Oithona similis and Acartia spp.). Vertical distribution of the mesozooplankton was characterized by copepod dominance at each sampled layer. There were no significant correlations among physical variables and biological parameters, except negative correlation for the mean biomass and mean water temperature.     

Proleptusmackenzieisp.n. (Nematoda, Spirurida) from Raja fyllae in the Barents Sea

Previous work on species of Proleptus Dujardin, 1845 and related genera is briefly reviewed. Proleptus mackenziei sp.n. is described and figured. P. mackenziei is close to P. obtusus, P. acutus and P. malayi but differs from them in the host, position of the vulva which is 2/5/ of the body length from the anus and in the detailed arrangements of the papillae on the male tail.     

Summer mesozooplankton distribution near Novaya Zemlya (eastern Barents Sea)

Regional variations in mesozooplankton composition, abundance and biomass were studied during a cruise in August 2006 near Novaya Zemlya Archipelago (eastern Barents Sea) using Juday net hauls from the bottom (or 100 m depth) to the surface. A comparison with multiannual literature values revealed that the mean temperature and salinity in the south and centre of the study area were similar to typical values, while temperature in the north was significantly higher. A total of 36 species and higher taxa were identified. Mesozooplankton abundance and biomass varied from 47 to 851 ind m⁻³ and from 5 to 74 mg dry weight m⁻³, respectively. Copepods dominated the mesozooplankton community, reaching 73–98% and 61–97% of the total abundance and biomass. Calanus finmarchicus and Oithona similis were the most abundant species at all stations. The biodiversities (Shannon indices) of the mesozooplankton community varied between stations from 1.10 to 2.46 (estimated from species abundances) and from 0.19 to 1.92 (estimated from species biomasses), averaging 1.93 ± 0.127 and 1.34 ± 0.151, respectively. Three groups at the 48% level of dissimilarity of species abundance were delineated by cluster analyses. The clusters differed significantly with respect to temperature and salinity. The total mesozooplankton abundance and biomass as well as quantitative parameters of most common taxa scaled negatively with temperature.