*This Work represents a part of a dissertation submitted to the University of Washington in partial fulfillment of the requirements for the Ph.D. Degree granted in August, 1964. I am reatly indebted to Dr R. L. Fernald for his advice and encoragemetn throughout the research. I am also grateful to Dr J. D. Mizelle and Dr W. H. Hsu for reading the manuscript and offering many useful suggestions.
Some observations on the development and cyclic changes of the oöcytes in a brooding starfish, Leptasterias hexactis
Article first published online: 20 AUG 2009
Journal of Zoology
Volume 154, Issue 4, pages 453–461, April 1968
How to Cite
Chia, F.-S. (1968), Some observations on the development and cyclic changes of the oöcytes in a brooding starfish, Leptasterias hexactis. Journal of Zoology, 154: 453–461. doi: 10.1111/j.1469-7998.1968.tb01677.x
- Issue published online: 20 AUG 2009
- Article first published online: 20 AUG 2009
- Accepted 10 October 1967
There are two ovaries in each arm and each ovary bears a single oviduct which opens orally at the interradial angle. The ovarian wall consists of three layers: mesothelium, muscular-connective tissue layer and germinal epithelium. The haemal space between the germinal epithelium and muscular-connective tissue layer is filled with a PAS positive fluid. It is suggested that this space may provide storage and transportation of nutrient to the germ cells.
The oögonium, situated along the germinal epithelium, is distinguished from the surrounding follicle cells by its clear cytoplasm and large nucleus with a single nucleolus. It measures 10 to 15 μ in diameter.
The development of primary oöcytes is divided into premeiotic, growth and germinal vesicle migration stages. The distribution of mitochondria seems to indicate the existence of a definite polarity in the young oöcytes; but this soon disappears at the beginning of vitellogenesis. Morphological evidence seems to suggest that some of the yolk granules may be synthesized first in follicle cells and then transferred into the oöcyte. Histochemical tests indicate that the yolk platelet is a carbohydrate-protein-lipid complex.
The first meiotic division occurs six hours after sperm penetration and the second meiotic division follows two hours later.
Monthly measurement of the oöcyte throughout a year indicates a well-defined annual spawning cycle; however, the growth of an oöcyte from an oögonium to a mature oöcyte requires about two years.