holoblastic


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holoblastic

[¦häl·ə¦blas·tik]
(embryology)
Pertaining to eggs that undergo total cleavage due to the absence of a mass of yolk.
References in periodicals archive ?
From studies in Caridina multidentata, Crangon crangon, Atyephyra compresa, and various species from the genus Alpheus, early cleavage is known to vary from holoblastic to incomplete (Brooks and Herrick, 1891; Weygoldt, 1961; Anderson, 1973; Klann and Scholtz, 2014).
Janolus fuscus followed the typical holoblastic, spiral cleavage pattern conserved within annelids, molluscs, and nemerteans.
scaura: (1) transition from holoblastic cleavage to superficial cleavage, (2) germdisc condensation, (3) germband formation and elongation, (4) germband flexure and limb bud formation, (5) limb bud elongation and segmentation, and (6) dorsal closure and reversal of cephalic direction.
The early holoblastic cleavages are diagrammed in Fig.
Owenia collaris embryos undergo holoblastic spiral cleavage to form a coeloblastula, which, although exceptionally hollow (again like some nemerteans), conforms to the ancestral pattern for annelids (Okada, 1970).
Early cleavage was radial and holoblastic. The earliest embryos encountered in the gonad were wrinkled blastulae (Fig.
pentagona through the stages of holoblastic radial cleavage, early blastula, wrinkled blastula, and gastrula was typical of development in lecithotrophic sea stars (Byrne, 1995).
Cleavage was equal, radial, complete (i.e., holoblastic), and rapid, dividing the embryo into a ball of cells (blastomeres).
Although microtubules have been correlated with cytoplasmic movements that follow fertilization in amphibians (4), ascidians (5), and annelids (6), these embryos do not form blastodisc caps and, unlike the squid, they undergo complete or holoblastic cleavage.