Hostname: page-component-78c5997874-s2hrs Total loading time: 0 Render date: 2024-11-15T21:41:30.403Z Has data issue: false hasContentIssue false

Gametogenesis and fertilization in the Mesozoan Dicyema aegira

Published online by Cambridge University Press:  06 April 2009

C. R. Austin
Affiliation:
Institute for Space Biosciences, Florida State University, Tallahassee, Florida, U.S.A.

Extract

Evidence is presented of a periodicity of oogenesis and spermatogenesis in D. aegira. Pauses in oogenesis were detected between successions of oogonial divisions; in spermatogenesis, the intervals appeared to be longer and the pauses came before division of primary spermatocytes. Regulation of division rates was such that between two and three times as many spermatozoa as oocytes were produced.

Observations indicated that spermatozoa emerged from the axial cell soon after their formation and made contact with oocytes early, often before these were fully grown. Properties of the oocyte cell membrane evidently precluded precocious sperm entry and the penetration of more than one spermatozoon.

Sincere thanks are due to Dr R. B. Short, who kindly made available all the material, and to Dr S. W. Fox and Dr C. B. Metz for the excellent facilities provided. This work was supported by P. H. S. Research Grant E 4749 (Institute of Allergy and Infectious Diseases) awarded to R. B. Short, and by N.A.S.A. Grant NsG–173–62 and N.S.F. Grant G–9150. Contribution No. 019 of the Institute for Space Biosciences.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1964

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

McConnaughey, B. H. (1951). The life cycle of the dicyemid mesozoa. Univ. Calif. Publ. Zool. 55, 295336.Google Scholar
McConnaughey, B. H. & Kritzler, H. (1952). Mesozoan parasites of Octopus vulgaris, Lam. from Florida. J. Parasit. 38, 5964.Google Scholar
Nouvel, H. (1947). Les dicyemides. Lree partie: systematique, generations vermiformes, infusorigene et sexualitè. Archs. Biol., Paris, 58, 59.Google Scholar
Short, R. B. (1957). Dicyemid mesozoans from the Gulf of Mexico. J. Parasit. 43, (Suppl.), 37.Google Scholar