The primordial, fluid-filled cavity inside the early forms of embryo, e.g. of blastula.
The presence of this cavity indicates that the embryo is in blastula stage following morula. This cavity is important in the later gastrulation.
Word origin: Greek blastos, bud.
Related forms: blastocoelic (adjective.)
- blastocyst cavity
- cleavage cavity
- segmentation cavity
See also: blastula