Hostname: page-component-586b7cd67f-r5fsc Total loading time: 0 Render date: 2024-12-01T12:07:39.849Z Has data issue: false hasContentIssue false

The Life History of Merocystis Kathae in the Whelk, Buccinum undatum

Published online by Cambridge University Press:  06 April 2009

Ruth Patten
Affiliation:
Department of Zoology, Trinity College, Dublin

Extract

1. The life history of Merocystis kathae shows that development follows a seasonal course. The youngest stages may appear in the kidney any time between March and June. Growth proceeds and sexual differentiation takes place but mature gametes are not found until November, when the first stages of sporogony also make their appearance. Mature spores containing sporozoites are formed in January and become increasingly common up to May. Degenerating stages of spores are common in summer.

2. The smallest parasites within the cells of the kidney are about 10μ. Growth occurs in the intracellular condition. The karyosome is complex, and contains a chromatinic body; in older parasites no chromatin reaction is given by the nucleus outside the karyosome.

3. Sexual differentiation is not perceptible until growth is almost complete.

4. In the female the intrakaryosomic body emerges, though a large karyosomic remnant remains until after fertilisation. Very fine granules of chromatin reappear in the nucleus, and form a fine network, which incorporates the intrakaryosomic body, and later forms the characteristic prefertilisation ‘cobweb’ nucleus. This network contracts in the mature macrogamete. Meantime the parasite has become free of its host cell, and the cytoplasm stains more intensely.

5. In the male, the elongated karyosome breaks down, generally completely, leaving the centrally placed chromatin body surrounded by a ring (in sectional view), of deeply stained material containing granules of chromatin, into which the central body passes as in the female. The male is released from the host cell, and, as in the female an alteration of the cytoplasmic staining occurs.

6. The nucleus, in the male parasite, moves to the surface, and undergoes repeated divisions until approximately 32 nuclei are formed. Cleavage of the cytoplasm brings about the formation of uninucleate cytomeres; within each of these are produced many nuclei, which lie near the surface, and finally become the microgametes.

7. After the macrogamete is fertilised, a thick membrane is formed outside the zygote. The nucleus assumes the characteristic spindle shape and subsequently divides.

8. Nuclear divisions proceed, until finally a great number of cone-shaped nuclei are found on the surface. This becomes folded and the nuclei sink in, and each is surrounded by a portion of cytoplasm to form a sporoblast. A single nuclear division then occurs, and the two nuclei elongate to form sporozoites each with a small cytoplasmic body.

9. Nuclear divisions are mitotic, but the longitudinal splitting of the chromosomes occurs without contraction. It is probable that ‘amitotic’ appearances are due to the incomplete incorporation of these long chromosomes at the telophase poles, and the multipolar divisions to the subsequent division of such ‘amitotic’ resting nuclei. Six chromosomes can be seen at the anaphase poles, but each is looped back so that it is V or J shaped. This chromosome number is characteristic of the divisions of both microgametogenesis and sporogony.

10. There is good evidence that, as in other Coccidia, reduction division occurs in the zygote, and that this is therefore the only diploid phase.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1935

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

Bělař, K. (1926 a). Zur Zytologie vo. Aggregata eberthi. Arch. Protistenk. 53, 312.Google Scholar
Bělař, K. (1926 b). Der Formwechsel der Protistenkerne. Ergbn. Zool. 6, 235.Google Scholar
Brasil, L. (1904). Sur une coccidie nouvelle parasite d'un cirratulium. C.R. Acad. Sci., Paris, 139, 645.Google Scholar
Darin, W. J. (1911). Notes on a new coccidian (Merocystis kathae n.gen. n.sp.). Arch. Protistenk. 23, 145.Google Scholar
Debaisieux, P. (1922). Note sur deux coccidies des mollusques: Pseudoklossia (?) patellae et chitonis. Cellule, 32, 231.Google Scholar
Dehorne, A. (1930 a). Sur l'Aggregata de Nereis diversicolor. C.R. Soc. Biol., Paris, 103, 665.Google Scholar
Dehorne, A. (1930 b). Présence d'éléments du type sporozoite d'Aggregata dans les divers tissues des Polychètes. C.R. Soc. Biol. p. 959.Google Scholar
Dobell, C. (1914). Le cycle évolutif de l'Aggregata. Bull. Inst. océanogr. Monaco, No. 283.Google Scholar
Dobell, C. (1925). The life history and chromosome cycle of Aggregata eberthi. Parasitology, 17, 1.CrossRefGoogle Scholar
Dobell, C. and Jameson, A. P. (1915). The chromosome cycle in Coccidia and Gregarines. Proc. roy. Soc. B, 89, 83.Google Scholar
Duboscq, O. (1918). Selysina perforans (Dub.). Arch. Zool. exp. gén. 58, 1.Google Scholar
Foulon, C. (1919). Merocystis kathae Dakin une Aggrégate de Buccinum undatum. Cellule, 30, 123.Google Scholar
Goodrich, H. Pixell (1914). The sporogony and systematic position of the Aggregatidae. Quart. J. micr. Sci. 60, 159.Google Scholar
Hentschel, C. C. (1926). On the correlation of the life history of the Acephaline Gregarine Gonospora, with the sexual cycle of its host. Parasitology, 18, 137.CrossRefGoogle Scholar
Hentschel, C. C. (1930). On the correlation of the life history of the Acephaline Gregarine Gonospora, with the sexual cycle of its host. Parasitology 22, 505.CrossRefGoogle 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
Jameson, A. P. (1920). The chromosome cycle of gregarines, with special reference to Diplocystis schneideri. Quart. J. micr. Sci. 64, 207.Google Scholar
Kunze, W. (1907). Übe. Orcheobius herpobdellae Schuberg et Kunze, ein Coccidium aus Herpobdella atomaria, Arch. Protistenk. 9, 381.Google Scholar
Lermantoff, E. (1913). Über Myriospora trophoniae, n.gen. n.sp. Arch. Protistenk. 32, 205.Google Scholar
Moroff, T. (1908). Die bei den Cephalopoden vorkommenden Aggregataarten (etc.). Arch. Protistenk. 11, 1.Google Scholar
Naville, A. (1925). Recherches sur le cycle sporogonique des Aggregata. Rev. suisse Zool. 32, 125.Google Scholar
Naville, A. (1927 a). Le cycle chromosomique d'Urospora lagidis. Parasitology, 19, 100.CrossRefGoogle Scholar
Naville, A. (1927 b). Recherches sur le cycle évolutif et chromosomique de Klossia helicina. Arch. Protistenk. 57, 427.Google Scholar
Naville, A. (1931). Les Sporozoaires (cycles chromosomiques et sexualité). Meém. Soc. Phys. Genève, 41, fasc. i, p. 1.Google Scholar
Ray, H. N. (1930). Dorisiella scolelepidis n.gen., n.sp. Parasitology, 22, 471.CrossRefGoogle Scholar
Robertson, M. (1927). Notes on certain points in the cytology of Trypanosome raiae and Bodo caudatus. Parasitology 19, 375.CrossRefGoogle Scholar
Setna, S. B. and Bhatia, B. L. (1934). On some gregarines from the prawn, Parapeneopsis sculptilis. Parasitology 26, 34.CrossRefGoogle Scholar
Siedlecki, M. (1898). Étude cytologique et cycle évolutif de in coccidie de la seiche. Ann. inst. Pasteur, 12, 799.Google Scholar
Siedlecki, M. (1907). Caryotropha mesnilii. Bull. Acad. Sci. Cracovie, p. 453.Google Scholar
Thomas, J. A. (1930). Sur le sporozoaire (coccidie) parasite de Nereis diversicolor. C.R. Soc. Biol., Paris, 104, 138.Google Scholar
Vincent, M. (1927). On Léerella hydropori, a coceidial parasite of the malpighian tubules of Hydroporus palustris. Parasitology, 19, 394.CrossRefGoogle Scholar
Wenyon, C. M. (1926). Protozoology. 8°. 2 vols. London: Bailliére, Tindall and Cox.Google Scholar
Wedekind, G. (1927). Zytologische Untersuchungen an Barrouxia schneideri. Z. Zellforsch. 5, 505.CrossRefGoogle Scholar