develops from gastrula embryo stage 7 embryo stage 8 embryo Stage 8 starts with the rapid phase of germ band extension and ends with the beginning of mesodermal segmentation. By the end of this stage germ band extension has progressed to the point where the proctodeal opening is at about 60% egg length and the dorsal folds (transverse furrows) are no longer visible. Duration at 25 degrees C: approximately 30 minutes (190-220 minutes after egg laying). FBbt:00005322 fly_anatomy.ontology DEPRECATION WARNING.