Early developmental stages with visible cell cleavage were not found, but blastodisc
and late-stage eggs were collected in June (Table 3).
After fertilization, squid egg ooplasm streams toward the animal pole to create a clear lens-shaped blastodisc cap where meroblastic cleavage occurs (1).
Embryos were observed for at least 4 h after fertilization during blastodisc formation and after incubation overnight at 17 [degrees]C.
If no embryogenesis was apparent to the naked eye, the area of the yolk around the blastodisc
was salvaged and stored as described, but it was only possible to identify the sex in 5 of 11 cases where this was done (2 males, 3 females); failures to determine sex may represent cases where eggs were not fertilized, rather than PCR failure, although we cannot distinguish the two at present.
Typically, these eggs also exhibited a pink blastodisc
with adjoining vitelline blood vessels, visible through the shell ("candling," e.
divided after 35-60 min into two blastomeres.
The right uterus of the one gravid female observed during late September had one single ovum capsule with no visible embryos, along with several blastodisc
or nutritive capsules, whereas the contents of other uterus appeared to have been aborted.
After fertilization, cytoplasm streams from the vegetal region of the squid egg towards the animal cap to form a blastodisc
where meroblastic cleavage will occur [1, 2].
were produced as result of Blastulation process
The list of abnormalities found among early embryos includes enlarged segmentation cavity under the blastodisc
, developmental retardation or arrest, and abnormal cell proliferations during gastrulation (Fig.
7 [[micro]meter] ([Mathematical Expression Omitted], n = 5) below the surface of the blastodisc
Formation of the blastodisc
at the animal pole of zebrafish (Danio rerio) and loach (Misgurnus fossilis) eggs is inhibited by cytochalasin - cytochalasin B (CCB) in zebrafish (Katow, 1983) and cytochalasin D (CCD) in loach (Ivanenkov et al.