Spatio-temporal changes of morphological and life-history parameters in Daphnia galeata in a canyon-shaped dam lake.

We measured size structure, size-fecundity relationship, egg size, and filt ering setae length in Daphnia galeata sampled in Rimov Reservoir, as parame ters related to the amount of food and to the direct or indirect influence of planktivorous fish. Samples were taken at seven sites along the whole lo ngitudinal profile of the reservoir in one-month intervals in winter1995/19 96 and two- and three-week intervals in May and one-week intervals in June 1996. The amount of chlorophyll a was determined simultaneously. We used th e parameters of D. galeata population investigated for the characterization of the heterogeneity of feeding conditions and fish predation in the longi tudinal profile of the reservoir and in the course of time.