Name: swimming blastula stage
ECAO ID: 0000300
Definition: "The embryo has hatched from the fertilization envelope and swims freely. It is still a hollow sphere that is one cell layer thick, but the cells constituting the vegetal plate (i.e. located at the vegetal pole) have started thickening along the apico-basal axis, thereby creating a morphological landmark that enables orienting the embryo along the animal-vegetal axis. In addition, at the animal pole, the apical tuft composed of long and immotile cilia has continued expending."
|
|