Abstract
Encysted metacercariae of Clinostomum marginatum (Digenea) were obtained from tissues of yellow perch, Perca flavescens. The outermost wall (host response) as seen under electron microscopy consisted of a single, fibrous tissue layer, 10–25 Μm thick. The tissue contained flattened fibrocytes, small fat deposits, and vacuoles embedded between layers of collagen fibers. The cyst cavity was filled with small vesicles, crystals, and debris. No layer corresponding to the primary (parasite-produced) cyst wall secreted by most species of metacercariae was noted. To determine the permeability of the cyst wall, encysted worms were incubated under initial rate conditions with [3H] glucose, with and without the glucose transport inhibitors phlorizin and phloretin. After incubation, the worms were mechanically excysted, washed, and processed to determine glucose uptake rates. V max and K t were greater than those obtained for worms excysted prior to incubation with substrate. Moreover, the presence of phlorizin or phloretin in the incubation medium had no effect on glucose uptake by encysted worms. Thus, the selective permeability of the cyst wall permits free diffusion of glucose to the cutaneous transport systems of the worm, while restricting the movements of phlorizin and phloretin.
Similar content being viewed by others
References
Asanji MF, Williams MO (1973) The structure and histochemistry of some trematode metacercarial cysts. J Helminthol 47:353–368
Cheng TC (1973) General parasitology. Academic Press, New York
Dean JM, Goodnight CJ (1964) A comparative study of carbohydrate metabolism in fish as affected by temperature and exercise. Physiol Zool 37:280–299
Erasmus DA (1972) The biology of trematodes. Edward Arnold, London
Halton DW, Johnston BR (1982) Functional morphology of the metacercarial cyst of Bucephaloides gracilescens (Trematoda: Bucephalidae). Parasitology 85:45–52
Hunter GW, Dalton HC (1939) Studies on Clinostomum. V. The cyst of the yellow grub of fish (Clinostomum marginatum). Proc Helminthol Soc Wash 6:73–76
Kalantan AMN, Arfin M, Nizami WA (1986) Histochemical nature and origin of the metacercarial cyst of Clinostomum complanatum (Trematoda: Digenea). Trans Am Microsc Soc 105:290–295
Neame KD, Richards TG (1972) Elementary kinetics of membrane carrier transport. Wiley, New York
Osborn HL (1911) On the distribution and mode of occurrence in the United States and Canada of Clinostomum marginatum, a trematode parasitic in fish, frogs and birds. Biol Bull 20:350–366
Siddiqui AA, Nizami WA (1982) Seasonal population dynamics of the metacercariae of Clinostomum complanatum (Trematoda: Digenea) in relation to sex of the host. Riv Parassitol 43:275–279
Smyth JD, Halton DW (1983) The physiology of trematodes. Cambridge University Press, Cambridge
Thomas RE, Gallicchio V (1967) Metabolism of 14C-glucose by metacercariae of Clinostomum campanulatum (Trematoda). J Parasitol 53:981–984
Ugelm GL, Lee KJ (1985) Proterometra macrostoma (Trematoda: Azygiidae): Functional morphology of the tegument of the redia. Int J Parasitol 15:61–64
Ugelm GL, Larson OR (1987) Facilitated diffusion and active transport systems for glucose in metacercariae of Clinostomum marginatum (Digenea). Int J Parasitol 17:847–850
Author information
Authors and Affiliations
Additional information
This study was supported by a grant from the National Science Foundation (PCM-8203378) and by the Biology Department, University of North Dakota.
Rights and permissions
About this article
Cite this article
Larson, O.R., Uglem, G.L. & Lee, K.J. Fine structure and permeability of the metacercarial cyst wall of Clinostomum marginatum (Digenea). Parasitol Res 74, 352–355 (1988). https://doi.org/10.1007/BF00539457
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00539457