This spawning behavior explains the restricted perivitelline space
recorded in the eggs, which is characteristic of species without reproductive migration (NAKATANI et al.
At the egg cell membrane, there were microvilli projecting outward into the perivitelline space
Some of the oocytes were striped off expanded cumulus cells for visualization of the extruded first polar body in the perivitelline space
It was reported (1) that Heliocidaris eggs develop beneath the tightly fitting perivitelline space
and form a wrinkled blastula in order to increase the ratio of the embryonic surface to the available volume.
Sperm injected into the perivitelline space
with these caps still in place cannot fertilize the egg, she says.
4 mm with an ocular micrometer and having one or more of the morphological characteristics corresponding to cobia eggs--single, large (300 to 600 [micro]m), pigmented oil droplet, heavily pigmented embryo, or narrow perivitelline space
(Ditty and Shaw, 1992; Ditty, 2006)--were removed and preserved in 10% neutral buffered formalin.
There was an extrusion of the first polar body from the egg plasma membrane into the perivitelline space
at 8 9 min (Fig.
Within a minute postinsemination, when the fertilization envelope could be identified, a number of particles were observed in the perivitelline space
(perivitelline-space particles) (Fig.
After enucleation, the nuclear donor cells were deposited into the perivitelline space
of enucleated oocytes to facilitate close membrane contact for subsequent fusion.
However, once the fertilization membrane is raised, the perivitelline space
exceeds the length of the nuclear filament, preventing other sperm from penetrating the egg.