Intra-clutch offspring size variability in the freshwater zooplankter Daphnia magna

Intra-clutch offspring size variability isquantified and compared in nine European populationsof the freshwater zooplankter Daphnia magna.Mean values for coefficients of variation forintra-clutch neonate body-length were low, andsimilar, within and between populations (range =1.8to 4.4%). There was little evidence that offspringsize variability increased with increasingenvironmental uncertainty and, under ’common garden‘laboratory conditions, maternal genotypes collectedfrom more uncertain environments did not produceclutches with a greater range of offspring sizes.Maternal body-length and growth rate did notsignificantly correlate with offspring sizevariability. However, there was a marginallysignificant positive correlation between clutch sizeand offspring size variability when data acrosspopulations were pooled.