What does blastulae mean?
Blastulae are early-stage animal embryos formed shortly after a fertilized egg begins to divide. Through repeated cell division known as cleavage, the single-celled zygote becomes first a solid cluster of cells (the morula) and then a hollow sphere — the blastula — whose central fluid-filled cavity is called the blastocoel. The word is almost exclusively used in embryology and developmental biology, appearing most often as the plural of blastula. Scientists study blastulae to understand how organisms establish their earliest body plans, since it is at this stage that cells begin to take on specialized fates before the embryo undergoes gastrulation and forms its germ layers. Though rarely encountered outside laboratory and textbook contexts, the term is memorable for marking a universal milestone: virtually every animal with more than a few cells passes through this hollow-ball phase of life.
nounThe plural form of blastula: an early-stage animal embryo consisting of a hollow sphere of cells (blastomeres) surrounding a fluid-filled cavity called the blastocoel, formed after repeated cleavage of the fertilized egg.
- Plural of blastula: early-stage animal embryos consisting of a hollow sphere of cells surrounding a fluid-filled cavity (the blastocoel), produced by cleavage of the fertilized egg.
"Under the microscope, the developing sea urchin blastulae appeared as delicate, translucent spheres."
"The researchers compared blastulae from several frog species to trace how early development varies across lineages."
"In vitro studies showed that only a fraction of the blastulae successfully implanted."
Every one of us was once a blastula — a microscopic hollow ball of cells — before we ever had organs, limbs, or even a nervous system.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of blastulae
Blastula derives from the Greek noun "blastos", meaning a bud, sprout, or germ, combined with the diminutive Latin suffix "-ula". The term entered scientific English in the late nineteenth century, when embryologists coined a family of "blasto-" terms — including blastocyst, blastema, blastocoel, and blastomere — to name successive stages and structures of early development. Its plural, blastulae, follows the Latin pattern for feminine nouns ending in -a.
Related word forms
How blastulae is actually used
A technical term confined chiefly to embryology and developmental biology. The Latin-style plural "blastulae" is standard; the anglicized "blastulas" is also accepted. Both forms refer to more than one blastula.
Easily confused with blastulae
Gastrulae are the later-stage embryos that form when a blastula undergoes gastrulation, developing distinct germ layers.
Morulae are the earlier, solid ball-of-cells stage that precedes the hollow blastula.