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A comparative study of the glandular and excretory systems of the oncomiracidia of the monogenean skin parasites Entobdella hippoglossi, E. diadema and E. soleae

Published online by Cambridge University Press:  06 April 2009

Graham C. Kearn
Affiliation:
School of Biological Sciences, University of East Anglia, Norwich, NOR 88C, U.K.

Extract

A comparison of the oncomiracidia of the monogenean skin parasites Entobdella hippoglossi from the halibut (Hippoglossus hippoglossus), E. diadema from the sting ray (Dasyatis pastinaca) and E. soleae from the skin of the common sole (Solea solea) has revealed the presence of ‘body gland cells’, all of which have openings on the ventral or lateral surfaces of the larvae. In all three species there are two pairs of glands lying in the posterior region of the body proper with long ducts extending into the haptor and opening on its ventral surface. In addition to these two pairs of glands there are seven other pairs of body glands in E. hippoglossi, six pairs in E. diadema and two pairs in E. soleae. In E. soleae all the ‘body gland cells’ are poorly developed in the oncomiracidium and are more conspicuous in post-oncomiracidia. The fate of the ‘body gland cells’ during post-oncomiracidial development has been studied in E. soleae, and their possible functions are discussed. The glands in the head region (anterior median, posterior median and lateral head glands) are similar in all three species. Gland cells associated with the alimentary system are less easy to observe but differences between the three species appear to be small.

In the oncomiracidia of all three species the number of flame cells and their distribution are the same, but the oncomiracidia of E. hippoglossi and E. diadema have loops in the excretory ducts anterior to the bladder and the bladders of E. diadema contain refringent bodies.

The oncomiracidial eyes of E. hippoglossi and E. soleae have lenses but the lenses are greatly reduced in the oncomiracidia of E. diadema. In the three larvae there are small but characteristic differences in the shapes of the accessory sclerites.

The oncomiracidium of E. hippoglossi has not previously been described.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1974

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References

REFERENCES

Hockley, D. J. (1973). Ultrastructure of the tegument of Schistosoma. Advances in Parasitology 11, 233305.CrossRefGoogle ScholarPubMed
Kearn, G. C. (1963 a). The egg, oncomiracidium and larval development of Entobdella soleae, a monogenean skin parasite of the common sole. Parasitology 53, 435–47.CrossRefGoogle Scholar
Kearn, G. C. (1963 b). Feeding in some monogenean skin parasites: Entobdella soleae on Solea solea and Acanthocotyle sp. on Raia clavata. Journal of the Marine Biological Association of the United Kingdom 43, 749–66.CrossRefGoogle Scholar
Kearn, G. C. (1968). The larval development of Merizocotyle sp., a monocotylid monogenean from the nasal fossae of Raia undulata. Parasitology 48, 921–8.CrossRefGoogle Scholar
Kearn, G. C. (1970). The oncomiracidia of the monocotylid monogeneans Dictyocotyle coeliaca and Calicotyle kroyeri. Parasitology 61, 153–60.CrossRefGoogle Scholar
Kearn, G. C. (1971). The attachment site, invasion route, and larval development of Trochopus pini, a monogenean from the gills of Trigla hirundo. Parasitology 63, 513–25.CrossRefGoogle Scholar
Kearn, G. C. (1973). An endogenous circadian hatching rhythm in the monogenean skin parasite Entobdella soleae, and its relationship to the activity rhythm of the host (Solea solea). Parasitology 66, 101–22.CrossRefGoogle Scholar
Kearn, G. C. (1974 a). The effects offish skin mucus on hatching in the monogenean parasite Entobdella soleae from the skin of the common sole (Solea solea). Parasitology 68, 173–88.CrossRefGoogle Scholar
Kearn, G. C. (1974 b). Nocturnal hatching in the monogenean skin parasite Entobdella hippoglossi from the halibut, Hippoglossus hippoglossus. Parasitology 68, 161–72.CrossRefGoogle ScholarPubMed
Kearn, G. C. & Baker, N. O. (1973). Ultrastructural and histochemical observations on the pigmented eyes of the oncomiracidium of Entobdella soleae, a monogenean skin parasite of the common sole, Solea solea. Zeitschrift für Parasitenkunde 41, 239–54.CrossRefGoogle ScholarPubMed
Llewellyn, J. (1963). Larvae and larval development of monogeneans. Advances in Parasitology 1, 287326.CrossRefGoogle ScholarPubMed
Lyons, K. M. (1970). The fine structure and function of the adult epidermis of two skin parasitic monogeneans, Entobdella soleae and Acanthocotyle elegans. Parasitology 60, 3952.CrossRefGoogle ScholarPubMed
Lyons, K. M. (1973 a). The epidermis and sense organs of the Monogenea and some related groups. Advances in Parasitology 11, 193232.CrossRefGoogle ScholarPubMed
Lyons, K. M. (1973 b). Epidermal fine structure and development in the oncomiracidium larva of Entobdella soleae (Monogenea). Parasitology 66, 321–33.CrossRefGoogle ScholarPubMed
Pearson, J. C. (1972). A phylogeny of life cycle patterns of the Digenea. Advances in Parasitology 10, 153–89.CrossRefGoogle ScholarPubMed