Fig. 5

Daphnia magna embryogenesis starting with germ cells still in the ovaries. Ovulation and deposition in the brood pouch and maturing ephippium over time in asexually (a) and sexually (b) produced embryos of Daphnia magna. Once (fertilized) germ cells are released from the ovaries, they are deposited in the maternal brood pouch (in asexually bred embryos) or in the developing ephippium (in sexually bred embryos). While asexually bred embryos develop directly, and first signs of morphological features are already observed 25 h post ovulation, sexually bred embryos are maintained in the sclerotizing and darkening ephippium. About 74 h post ovulation the mother molts and thereupon sheds the ephippium. The embryos in the ephippium have arrested in diapause already 50 h post ovulation. Development progresses upon diapause termination by exogenous factors. Stages indicate the time points used for fluorescent (immune)-labelling