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A simple, hollow blastula with a single-layered wall.



a stage of embryonic development; a type of blastula. The coeloblastula is characteristic of certain Coelenterata, lower Arthropoda, Echinodermata, Tunicata, Acrania, Cyclostomata, Acipenseridae, and most Amphibia. It is formed as a result of complete radial cleavage (even or uneven). It resembles a bubble filled with fluid.

References in periodicals archive ?
By the time a coeloblastula forms, most zooxanthellae are located in individual blastomeres, at one end of the coeloblastula.
Twenty hours after spawning, the motile coeloblastulas began to show a slight depression at the pole about which the algae were concentrated.
An amphiblastula or coeloblastula is produced by calcareous sponges; a parenchymella is the larva of the majority of demosponges, but several other larval types are known; and a trichimella is exclusive to hexactinellid sponges.
In this study we will show the fine structure of the coeloblastula, metamorphosing larva, and juvenile sponge of Leucosolenia laxa in clear electron micrographs.
The coeloblastula is a hollow spheroid consisting of a layer of flagellated cells around a large central cavity (Fig.
Figure 2 shows the flagellated cells of the coeloblastula of L.
Vesicular cells in the coeloblastula are also described for the first time.