Period | Stage | Developmental time at 28°C | Characteristic features in whole mounts | |
---|---|---|---|---|
Hours | %* | |||
Cleavage | 1A | 0–6 | 1.8 | Nuclei divide internally |
1B | 6–12 | 3.6 | Nuclei reach the periphery | |
Blastoderm | 2A | 12–18 | 5.3 | Formation of germ rudiment |
2B | 18–24 | 7.1 | Nuclei progressively concentrate at egg posterior | |
Gastrulation | 3A | 24–30 | 8.9 | Germ rudiment invagination begins |
3B | 30–36 | 10.7 | Germ band extension | |
Segmentation | 4 | 36–48 | 14.3 | Anterior segmentation (in head and thorax) begins |
5 | 48–60 | 17.9 | Appendage buds appear; non-segmented abdomen | |
6 | 60–72 | 21.4 | Appendages grow; | |
segmented abdomen; neural groove evident | ||||
Growth | 7 | 72–84 | 25 | Thoracic appendages elongate, bigger than head appendages |
8 | 84–96 | 26.6 | Antennal appendages grow over first maxillary appendages | |
9 | 96–108 | 32 | First maxillary appendages hidden by antennal appendages; embryo shortens and widens (germ band retraction) | |
Katatrepsis and Dorsal Closure | 10 | 108–132 | 35 | At the end of katatrepsis, embryo and egg anterior-posterior axes coincide; embryo closes dorsally |