blastula vs blastular

blastula is a noun but blastular is not a noun.

Word	Noun	Adjective	Verb	Adverb
blastula	Yes	No	No	No
blastular	No	Yes	No	No

blastula (noun)	blastular (noun)
early stage of an embryo produced by cleavage of an ovum; a liquid-filled sphere whose wall is composed of a single layer of cells; during this stage (about eight days after fertilization) implantation in the wall of the uterus occurs

blastula (adjective)	blastular (adjective)
	of or relating to a blastula