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The oncomiracidium and post-oncomiracidial development of the hexabothriid monogenean Rajonchocotyle emarginata

Published online by Cambridge University Press:  06 April 2009

Maureen Wiskin
Maureen Wiskin
Affiliation:
Department of Zoology and Comparative Physiology, The University, P.O. Box 363, Birmingham 15, England
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Summary

A description is given of some features of the embryonic development, the structure of the oncomiracidium and the postlarval development of R. emarginata, a hexabothriid parasite on the gills of Raia clavata.

There are three phases in the larval development of the haptor of Rajonchocotyle: an oncomiracidial or marginal hook stage, a hamulus stage and a sucker stage. Neither the embryo nor the oncomiracidium ever possesses more than five pairs of marginal hooks and marginal hooks I (the posterior-most pair) are considered to be missing. The marginal hooks develop within distinct binucleate oncoblasts. During the early stages of post-oncomiracidial growth the secondary attachment organs of the haptor are formed and it is only after the completion of the development of the haptor that the reproductive organs begin to appear. Firstly, a pair of hamuli is acquired, followed by four pairs of suckers, which form in posterior-anterior succession at the site of marginal hooks III-VI. The first pair of suckers remains unarmed while the other three pairs acquire hooked sclerites and become the main functional attachment organs of the adult. As the first pair of suckers appears the posterior part of the haptor lengthens to form a caudal appendage. Hexabothriids are considered to show closer affinity to the 8-suckered chimaericolids and diclidophorids than to the 6-suckered polysto-matids, the unarmed suckers representing a simplification, by loss of the sclerite and reduction in sucker size, of an originally armed sucker.

I would like to express my thanks to Dr J. Llewellyn for his interest and for much helpful discussion.

Thanks are also due to the Director and Staff of the Marine Biological Association at Plymouth, in particular Mr J. E. Green for material and assistance, and to Dr A.j Brinkmann, of the Department of Zoology, University of Bergen, for supplying specimens of Squalonchocotyle borealis.

Type
Research Article
Information
Parasitology , Volume 60 , Issue 3 , June 1970 , pp. 457 - 479
Copyright
Copyright © Cambridge University Press 1970

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References

Brinkmann, A. Jr (1940). Contributions to our knowledge of the Monogenetic Trematodes Bergens museums ålrbog. Naturvitenskapelig rekke, 1.Google Scholar
Bychowsky, B. E. (1957). Monogenetic Trematodes, their Classification and Phylogeny 509 pp. Moscow, Leningrad: Academy of Sciences, U.S.S.R. (English translation edited by W. J. Hargis, 1961. Washington: American Institute of Biological Sciences.)Google Scholar
Cerfontaine, P. (1899). Contribution á l'étude des octoeotylides. V. Les onchocotylinae. Archives de Biologie, Paris 16, 345–478.Google Scholar
Euzet, L. (1957 a). Larves gyrodaetyloides nageantes de quelques Microcotylidae (Trematoda-Monogenea). Bulletin de la Société neuchâteloise des sciences naturelles (Natur) 80, 187–94.Google Scholar
Euzet, L. (1957 b). La larve gyrodactyloide nageante de Calicotyle kröyeri Diesing 1850. Trematoda-Monogenea. Annales de parasitologie humaine et comparée, Paris 32, 197–9.Google Scholar
Euzet, L. & Raibaut, A. (1960). Le développement post-larvaire de Squalonchocotyle torpedinis (Price, 1942) (Monogenea, Hexabothriidae). Bulletin de la Société neuchâteloise des sciences naturelles (Natur) 81, 101–8.Google Scholar
Halkin, H. (1901). Recherches sur la maturation, la fécondation et le développement du Polystomum integerritnum. Archives de biologie, Paris 18, 291–363.Google Scholar
Kearn, G. C. (1963). The egg, oncomiracidium and larval development of Entobdella soleae, a monogenean skin parasite of the common sole. Parasitology 47, 21–9.Google Scholar
Kearn, G. C. (1965). The biology of Leptocotyle minor, a skin parasite of the dogfish, Scyliorhinus canicula. Parasitology 55, 473–80.CrossRefGoogle Scholar
Kearn, G. C. (1967). Experiments on host-finding and host-specificity in the monogenean skin parasite, Entobdella soleae. Parasitology 57, 584–605.CrossRefGoogle ScholarPubMed
Kearn, G. C. (1968). The development of the adhesive organs of some diplectanid, tetraonchid and dactylogyrid gill parasites (Monogenea). Parasitology 58, 149–63.CrossRefGoogle ScholarPubMed
Llewellyn, J. (1954). Observations on the food and gut pigment of the Polyopisthocotylea (Trematoda: Monogenea). Parasitology 44, 428–37.CrossRefGoogle ScholarPubMed
Llewellyn, J. (1957). The larvae of some monogenetic trematode parasites of Plymouth fishes. Journal of the Marine Biological Association of the United Kingdom, Plymouth 36, 243–59.CrossRefGoogle Scholar
Llewellyn, J. (1963). Larvae and larval development of monogeneans. Advances in Parasitology 1, 287–326.CrossRefGoogle ScholarPubMed
Llewellyn, J. (1965). The evolution of parasitic platyhelminths. Symposia. British Society for Parasitology 3, 47–78.Google Scholar
Llewellyn, J. (1968). Larvae and larval development of monogeneans. Advances in Parasitology 5, 373–83.CrossRefGoogle Scholar
Lyons, K. M. (1966). The chemical nature and evolutionary significance of monogenean attachment sclerites. Parasitology 56, 63–100.CrossRefGoogle ScholarPubMed
Rowan, W. B. (1956). The Mode of hatching of the egg of Fasdola hepatica. Experimental Parasitology 5, 118–37.CrossRefGoogle ScholarPubMed
Sproston, N. G. (1946). A synopsis of the monogenetic trematodes. Transactions of the Zoological Society of London 25, 185–600.CrossRefGoogle Scholar
Wilson, R. A. (1967). The structure and permeability of the shell and vitelline membrane of the egg of Fasdola hepatica. Parasitology 57, 47–58.CrossRefGoogle Scholar
Yamaguti, S. (1963). Systema Helminthum, vol. 4. Monogenea and Aspidocotylea, 699 pp. New York, London: Interscience.Google Scholar