The opening of the central cavity of an embryo in the early stage of development.
- ‘Arrow worms were considered deuterostomes based on their tripartite coelom and the retention of the blastopore to form the anus.’
- ‘One group, including amphioxus, lampreys, sturgeons and amphibians, displays the primitive condition, with holoblastic eggs and involution of the endoderm through a blastopore.’
- ‘More accurately, the blastopore elongates along the future ventral midline and the mouth and anus develop at opposite ends.’
- ‘Both the fate of the blastopore and early embryonic cleavage patterns vary considerably among the Bilateria and have not been assessed experimentally in many species.’
- ‘In the complementary category of the protostomes, which includes annelids and arthropods, the blastopore develops into the mouth.’