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...

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...

Inland epigean freshwater amphipods of Romania are diverse and abundant for this region has a favourable geographical position between the Balkans and the Black Sea. Excluding Ponto-Caspian species originating in brackish waters and freshwater subterranean taxa, there are 11 formally recognized epigean freshwater species recorded from this country. They belong to 3 genera, each representing a d...

marine ecosystem pollution is one of the important problems of today environment. in this study the existence of heavy metal in the namrood river, situated in firoozkooh in tehran province, iran has been investigated. the namrood river is located near firoozkooh route, and is affected by pollutant from tourist centers, entertainment, gas stations, nearby villages’ sewage systems, farming efflue...