| the interactive effects of microcystin and nitrite on life-history parameters of the cladoceran daphnia obtusa. | elevated nitrite and microcystin concentrations co-occur during degradation of microcystis blooms and are toxic to aquatic organisms. we studied the relative and combined effects of these on daphnia obtusa life-history. nitrite and microcystin-lr treatments were: 0, 1, 3 mg l(-1) and 0, 10, 100, 300 µg l(-1), respectively. experiments were factorial with 12 treatment combinations. incubations were 15 d and recorded: moult number; time to first batch of eggs; time to first clutch; size at first b ... | 2011 | 21450401 |
| biotic ligand model prediction of copper toxicity to daphnids in a range of natural waters in chile. | the objective of this study was to assess the predictive capacity of the biotic ligand model (blm) for acute copper toxicity to daphnids as applied to a number of freshwaters from chile and to synthetic laboratory-prepared waters. thirty-seven freshwater bodies were sampled, chemically characterized, and used to determine the copper concentration associated with the 50% of mortality (lc50) for daphnia magna, daphnia pulex, and daphnia obtusa (native to chile). the data were then used to run thre ... | 2005 | 16111013 |
| population structure in daphnia obtusa: quantitative genetic and allozymic variation. | quantitative genetic analyses for body size and for life history characters within and among populations of daphnia obtusa reveal substantial genetic variance at both hierarchical levels for all traits measured. simultaneous allozymic analysis on the same population samples indicate a moderate degree of differentiation: gst = 0.28. no associations between electrophoretic genotype and phenotypic characters were found, providing support for the null hypothesis that the allozymic variants are effec ... | 1993 | 8244001 |