This study presents the diversity and structure of pelagic zooplankton in north-eastern Poland. The research was conducted 47 lakes with different trophic conditions middle summer. Samples were collected close to deepest part avoid diverse benthic littoral zones. We found 119 species which 32 Cladocera, 16 Cyclopoida, 4 Calanoida, 67 Rotifera. determined occurred most frequently region, as well...

A total of 246 perch Perca fluviatilis L. fry, 20 to 106 d old from 3 different reservoir subpopulations (epipelagic perch fry, EPF; bathypelagic perch fry, BPF; littoral perch fry, LPF), were examined for parasites. Six species of endoparasites were found: the nematode Camallanus lacustris was the most common, followed by the cestodes Proteocephalus percae, Bothriocephalus claviceps, Glanitaen...

Measurement of evolutionary adaptations of a visual system to its visual and operational ecology requires comparison of visual function in different species with similar morphologies and visual ecologies, occupying the same habitats but displaying differences in visually-guided behavior. The goal here was to document the biophysical properties of photoreceptors in the lesser water boatman Corix...

In one of the simplest metazoan organisms, the sponge Spongilla lacustris, at least four different src-related kinase genes (srk1-4) are expressed, all of which show a high degree of similarity to the c-src genes of vertebrates. Whereas srk2 and srk3 are clearly unrelated at the nucleic acid level, srk1 and srk4 share identical sequences in the 5' parts of their cDNAs. The cloning of several pr...

SUMMARYVertically transmitted parasites may have positive, neutral or negative effects on host fitness, and are also predicted to exhibit sex-specific virulence to increase the proportion or fitness of the transmitting sex. We investigated these predictions in a study on the survival and sex ratio of offspring of the amphipod Gammarus roeseli from females infected by the vertically transmitted ...

A laboratory-based study was performed to assess the impact of climate warming on the recruitment of the endangered population of the European lobster (Homarus gammarus) at Helgoland (North Sea, German Bight). Egg-bearing females collected in situ just after spawning in late summer were subjected to various seasonal temperature regimes. Regimes with elevated temperatures (mild winters) resulted...

Abstract The purpose of this study is to determine the parameters reproductive biology seven commercial species at Ramsar Site Baixada Maranhense support fisheries management measures. collections were carried out between 2012 and 2016. period, sex ratio, weight-length relationship first sexual maturity evaluated for importance. ratio showed that females are predominant all species, except Plag...

The purpose of this toxicity test was to determine the reliability and comparability of Cu++ toxicity on Gammarus fasciatus. The study was conducted to compare toxicity results for Rainbow trout, Salmo ~airdneri Richardson, another coldwater poikilotherm. Since G. fasciatus comprises a major portion of the diet of many freshwater fishes, it can be stated to be an "important" species (PATRICK et...

The conversion of riparian forests into agricultural land results in the loss water quality and aquatic biota health. objectives this study were therefore to determine proportion use with emphasis on type vegetation cover; evaluate limnological parameters concentration inorganic elements São José stream Dourados River Basin, Mato Grosso do Sul, Brazil; correlate concentrations water; risk prese...