The acute toxicity of selected alkylphenols to young and adult Daphnia magna

Differences in sensitivity toward toxicants between young and adult individuals in a population are assumed to be primarily associated with their difference in body size. This assumption plays a key role in the modeling of effects of variable concentrations of toxicants on nonhomogeneous populations. The hazardbased no-effect-concentrations ...

The ecotoxicity and the biodegradability of lactic acid, alkyl lactate esters and lactate salts

The ecotoxicity of lactic acid, its alkyl esters and selected metal salts was studied experimentally with the micro alga Selenastrum capricornutum, the crustacean Daphnia magna and the fish species Brachydanio rerio and Pimephales promelas. In addition, the biodegradation of lactate esters was also studied. The aim of the study was to provide...

Effects of chlorpyrifos on individuals and populations of Daphnia pulex in the laboratory and field

Effects of the insecticide chlorpyrifos (cpf) on young (<l d old) and adult (7-9 d old) Daphnia pulex and the ability of D. pulex to recover after exposure were tested in the laboratory. Populations of D. pulex exposed to cpf were studied in the laboratory and field. In the field, cpf was applied in a single dose. The effects of that dose on D....

Watervlo vrouw met mannelijk borsthaar: De endocrine activiteit van alkylfenolen bij Daphnia magna

Superparasitism as an ESS: To reject or not to reject, that is the question

A stochastic model is formulated to determine the optimal strategy for a solitary parasitoid which has discovered an already parasitized host. The model assumes that the parasitoid can count both the number of eggs already present in a host and the number of conspecifics searching in the same patch. The survival probability of an egg is assumed...

Population consequences of a physiological model for individuals

On conjugative plasmids: mathematical models of their population dynamics and population genetics