part of part of Danio rerio blastopore https://github.com/obophenotype/uberon/issues/660 AAO:0000045 UBERON:0000100 BTO:0001695 In protostome development, the first opening in development, the blastopore, becomes the animal's mouth; In deuterostome development, the blastopore becomes the animal's anus Wikipedia:Blastopore XAO:0000208 The orifice of invagination of the endomesodermal cells during the embryonic stages of an organism. A slit-like invagination on the dorsal side of the blastula surface of the embryo where the mesoderm and endoderm move inside the embryo at gatrulation.[AAO] embryonic structure archenteron Christopher J. Mungall