Blastocoele

Blastocoel, blastocoelic or primary body cavity called the fluid-filled cavity of the blastula. The blastocoel is formed during ontogeny in the final stages of cleavage. In the course of ontogenesis ( cotyledon formation) is the blastocoel from the involuting endoderm (inner cotyledon ) almost completely replaced as part of gastrulation. The cavity of the blastula is not homologous to Blastocystenhöhle a blastocyst.