Hatching of Daphnia sexual eggs. I. Intraspecific differences in the hatching responses of D. magna eggs

SUMMARY To test the hypothesis that the variability in hatching response of the sexual eggs of Daphnia has a genetic component, hatching after a standardized decapsulation technique was studied in different D. magna families, resulting from intra‐ as well as interclonal crosses. There were significant differences in hatching response between families. Average hatching rates ranged from 0.0% to 81.9%, depending on the family under study. Offspring‐on‐parent regressions indicate that the hatching rate‐of sexual eggs is to a large extent determined by the genotype of the mother (maternal inheritance). Our results suggest that there is ample generic variation on a microgeographic scale for characteristics related to hatching of sexual eggs in Daphnia .