The Global Plankton Database: an inventory and data from the Former Soviet Union expeditions

At present time, there is a lack of knowledge on the interannual climate-related variability of zooplankton communities of the tropical Atlantic, central Mediterranean Sea, Caspian Sea, and Aral Sea, due to the absence of appropriate databases. In the mid latitudes, the North Atlantic Oscillation (NAO) is the dominant mode of atmospheric fluctuations over eastern North America, the northern Atlantic Ocean and Europe. Therefore, one of the issues that need to be addressed through data synthesis is the evaluation of interannual patterns in species abundance and species diversity over these regions in regard to the NAO. The database has been used to investigate the ecological role of the NAO in interannual variations of mesozooplankton abundance and biomass along the zonal array of the NAO influence. Basic approach to the proposed research involved: (1) development of co-operation between experts and data holders in Ukraine, Russia, Kazakhstan, Azerbaijan, UK, and USA to rescue and compile the oceanographic data sets and release them on CD-ROM, (2) organization and compilation of a database based on FSU cruises to the above regions, (3) analysis of the basin-scale interannual variability of the zooplankton species abundance, biomass, and species diversity.

ON PARADICRANOPHORUS-ACULEATUS (NEISTWESTNOVA-SHADINA, 1935) WITH REMARKS ON ALL OTHER SPECIES OF THE GENUS (ROTIFERA, DICRANOPHORIDAE)

In 1934, the rotifer Paradicranophorus aculeatus was discovered by NEISTWESTNOVA-SHADINA in the River Oka near Murom (Russia). She described it as a Dicranophorus species. In 1958, the rheophilic rotifer was rediscovered in the Polish River Grabia by PAWLOWSKI. This paper reports a third occurence in three samples from the Yun Nan Luoxiao River in China, allowing additional studies of this rare species.

Habitat-specific adaptation of immune responses of stickleback (Gasterosteus aculeatus) lake and river ecotypes

Freshwater populations of three-spined sticklebacks (Gasterosteus aculeatus) in northern Germany are found as distinct lake and river ecotypes. Adaptation to habitat-specific parasites might influence immune capabilities of stickleback ecotypes. Here, naive laboratory-bred sticklebacks from lake and river populations were exposed reciprocally to parasite environments in a lake and a river habitat. Sticklebacks exposed to lake conditions were infected with higher numbers of parasite species when compared with the river. River sticklebacks in the lake had higher parasite loads than lake sticklebacks in the same habitat. Respiratory burst, granulocyte counts and lymphocyte proliferation of head kidney leucocytes were increased in river sticklebacks exposed to lake when compared with river conditions. Although river sticklebacks exposed to lake conditions showed elevated activation of their immune system, parasites could not be diminished as effectively as by lake sticklebacks in their native habitat. River sticklebacks seem to have reduced their immune-competence potential due to lower parasite diversity in rivers

Divergent Macroparasite Infections in Parapatric Swiss Lake-Stream Pairs of Threespine Stickleback (Gasterosteus aculeatus)

Spatial heterogeneity in diversity and intensity of parasitism is a typical feature of most host-parasite interactions, but understanding of the evolutionary implications of such variation is limited. One possible outcome of infection heterogeneities is parasite-mediated divergent selection between host populations, ecotypes or species which may facilitate the process of ecological speciation. However, very few studies have described infections in population-pairs along the speciation continuum from low to moderate or high degree of genetic differentiation that would address the possibility of parasite-mediated divergent selection in the early stages of the speciation process. Here we provide an example of divergent parasitism in freshwater fish ecotypes by examining macroparasite infections in threespine stickleback (Gasterosteus aculeatus) of four Swiss lake systems each harbouring parapatric lake-stream ecotype pairs. We demonstrate significant differences in infections within and between the pairs that are driven particularly by the parasite taxa transmitted to fish from benthic invertebrates. The magnitude of the differences tended to correlate positively with the extent of neutral genetic differentiation between the parapatric lake and stream populations of stickleback, whereas no such correlation was found among allopatric populations from similar or contrasting habitats. This suggests that genetic differentiation is unrelated to the magnitude of parasite infection contrasts when gene flow is constrained by geographical barriers while in the absence of physical barriers, genetic differentiation and the magnitude of differences in infections tend to be positively correlated.

Distinctive insular forms of threespine stickleback (Gasterosteus aculeatus) from western Mediterranean islands

Neutral and adaptive variation among populations within a species is a major component of biological diversity and may be pronounced among insular populations due to geographical isolation and island specific evolutionary forces at work. Detecting and preserving potential evolutionary significant units below the species rank has become a crucial task for conservation biology. Combining genetic, phenotypic and ecological data, we investigated evolutionary patterns among the enigmatic threespine stickleback populations from western Mediterranean islands, all of which are threatened by habitat deterioration and climate change. We find indications that these populations derive from different genetic lineages, being genetically highly distinct from the stickleback of mainland Europe and the northern Atlantic as well as from each other. Mediterranean island stickleback populations are also phenotypically distinct from mainland populations but interestingly stickleback from Iceland have converged on a similar phenotype. This distinctive island stickleback phenotype seems to be driven by distinct selective regimes on islands versus continents. Overall, our results reveal the status of western Mediterranean island stickleback as evolutionarily distinct units, important for conservation of biodiversity.

Meine Beobachtungen beim Brutgeschäft des drei- und zehnstachligen Stichlings (Gasterosteus aculeatus u. G. pungitius) im Aquarium

Von Bernh. Wichand

Meine Beobachtungen beim Brutgeschäft des drei- und zehnstachligen Stichlings (Gasterosteus aculeatus u. G. pungitius) im Aquarium : Schluß

Von Bernh. Wichand

Beobachtungen beim Brutgeschäft des dreistachligen Stichlings (Gasterosteus aculeatus)

Von L. Lauppe