Solar simulator irradiation of an aqueous suspension of prednisone, a widely prescribed drug, produces seven photochemical derivatives. The compounds have been identified on the basis of their physical features. All the chemicals have been tested to evaluate their toxic effects on freshwater organisms from different trophic levels. The rotifer Brachionus calyciflorus and two crustaceans, the cl...

The purpose of this study was to evaluate the effects of four diets on the results of seven-day Ceriodaphnia dubia toxicity tests. Survival and reproduction were used as indices to detect the sensitivity of this species to acute and chronic copper stress. All toxicity tests were conducted using the moderately hard reconstituted water recommended in 1989 by the U.S. Environmental Protection Agen...

Recruitment success of roach varied dramatically between 1979 and 1982 in Alderfen Broad, a small lake in eastern England. When fry were abundant (in 1979 and 198 1, but not in 1980 or 1982) the summer zooplankton became sparse and was dominated by copepods and rotifers. In years of good recruitment, as each of the preferred cladoceran prey species entered the diet of underyearling roach, its d...

The algorithm is suggested for selecting most appropriate and sensitive bioassay method to a particular type of pollution prevailing in the study area. bases on battery bioassays, which necessarily includes mortality test Daphnia magna Straus, 1820. Other approaches comparing sensitivity methods are selected aim. has been tested model situ samples. According proposed algorithm, tests D. Cerioda...

The planktonic cladocerans Ceriodaphnia richardi, Daphnia gessneri, and birgei inhabit the limnetic littoral zones of Lake Monte Alegre, where former species tends to be abundant. Laboratory experiments were carried out investigate competition for seston in using life table data. In experiment 1, C. richardi D. gessneri fed from zone (1–1.29 mg C L−1); 2, zone. Despite relatively high concentra...