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A Coccidian from the eggs of Thalassema neptuni Gaertner

Published online by Cambridge University Press:  06 April 2009

Doris L. Mackinnon
Affiliation:
From the Department of Zoology, King's College, London
H. N. Ray
Affiliation:
From the Department of Zoology, King's College, London

Extract

1. An account is given of a sporozoan parasite, hitherto known as Monocystis thalassemae Lankester, and its coccidian nature is demonstrated.

2. Schizogony and sporogony both occur in the eggs of Thalassema neptuni while these are in the genital pouches (nephridial sacs). Schizogony was observed on three occasions, and only the later stages were seen.

3. The full-grown sexual parasites are vermiform and immobile. The males are smaller than the females.

4. The microgametocyte, when it becomes spherical, gives rise to very numerous, elongate microgametes, similar to those of Aggregata.

5. Fertilization has not been observed. The oocystic membrane is only sometimes formed and is always inconspicuous.

6. At all stages where a chromosome count was possible, the number of chromosomes was seven. The reduction division is zygotic. No polymitotic figures were observed either in microgametogenesis or in sporogony.

7. Numerous sporocysts are produced. These may contain as many as twelve nuclei, and presumably give rise to at least twelve sporozoites. The formation of sporozoites has not been observed by us, but was noted by Lankester.

8. A new coccidian genus, Ovivora, is created for this organism, which now becomes Ovivora thalassemae (Lankester) and is relegated to the subfamily Aggregatinae in Hoare's classification.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1937

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References

REFERENCES

Dobell, C. (1925). The life history and chromosome cycle of Aggregata eberthi. Parasitology, 17, 1.CrossRefGoogle Scholar
Goodrich, E. A. & Goodrich, H. L. M. P. (1921). Gonospora minchinii, n.sp., a gregarine inhabiting the egg of Arenicola. Quart. J. micr. Sci. 65, 157.Google Scholar
Hoare, C. A. (1933). Studies on some new ophidian and avian coccidia from Uganda, with a revision of the classification of the Eimeriidea. Parasitology, 25, 359.CrossRefGoogle Scholar
Lankester, E. R. (1881). On Thalassema neptuni Gaertner. Zool. Anz. 4, 350.Google Scholar
Lankester, E. R. (1885). Protozoa. In the Encyclopaedia Britannica, 9th ed.19, 350.Google Scholar
Lermantoff, E. (1913). über Myriaspora trophoniae, n.gen., n.sp., ein neues, in Trophonia plumosa parasitierendes Coccidium. Arch. Protistenk. 32, 205.Google Scholar
Mackinnon, D. L. & Ray, H. N. (1929). Lankester's “gregarine” from the eggs of Thalassema neptuni. Nature, Lond., 124, 877.CrossRefGoogle Scholar
Mackinnon, D. L. & Ray, H. N.(1931 a). Observations on dicystid gregarines from marine worms. Quart. J. Micr. Sci. 74, 439.Google Scholar
Mackinnon, D. L. & Ray, H. N.(1931 b). A new protozoon, Hyperidion thalassemae, n.gen., n.sp., from the intestine of Thalassema neptuni Gärtner. Quart. J. Micr. Sci. 74, 467.Google Scholar
Minchin, E. A. (1903). The Sporozoa. In Lankester's Treatise on Zoology, 1, Fasc. 2, 328.Google Scholar
Patten, R. (1935). The life-history of Merocystis kathae in the whelk, Buccinum undatum. Parasitology, 27, 399.CrossRefGoogle Scholar
Siedlecki, M. (1907). Caryotropha mesnilii. Bull. Acad. Sci. Cracovie, 453.Google Scholar