As nouns the difference between protostoma and protostome
is that protostoma
is blastopore while protostome
is any animal, of the former taxon protostomia
, in which the mouth is derived from the embryonic blastopore.
As nouns the difference between blastopore and protostoma
is that blastopore
is (embryology) the opening into the archenteron while protostoma