Blastocoel , blastocoelic or primary body cavity refers to the fluid filled cavity of the blastula . The blastocoel arises during ontogenesis in the final stage of the furrow . In the further course of ontogenesis, the blastocoel is almost completely displaced by the invaginating endoderm (inner cotyledon) in the course of gastrulation ( germ layer formation ) . The cavity of the blastula is not homologous to the blastocyst cavity of a blastocyst .
- Cleveland P. Hickman et al.: Zoology . Pearson Germany, 2008, ISBN 978-3-8273-7265-9 , pp. 244-245 .
- Secondary body cavity (Coelom)