Hostname: page-component-7c8c6479df-fqc5m Total loading time: 0 Render date: 2024-03-29T08:28:13.378Z Has data issue: false hasContentIssue false

Pollution toxicity to the transmission of larval digeneans through their molluscan hosts

Published online by Cambridge University Press:  10 November 2003

N. J. MORLEY
Affiliation:
School of Biological Sciences, Royal Holloway, University of London, Egham, Surrey, TW20 0EX, UK
S. W. B. IRWIN
Affiliation:
School of Biological and Environmental Sciences, University of Ulster, Jordanstown Campus, Shore Road, Newtonabbey, Co. Antrim, Northern Ireland, BT37 0QB, UK
J. W. LEWIS
Affiliation:
School of Biological Sciences, Royal Holloway, University of London, Egham, Surrey, TW20 0EX, UK

Abstract

The increased occurrence of pollutants in ecosystems is a continuing area of concern. It is known that numerous diseases of wild aquatic animals can occur with decreased or increased prevalences in areas associated with high or chronic levels of pollution. This may have serious implications for environmental health. There has consequently been an increasing number of laboratory and field studies on disease transmission under polluted conditions, especially focusing on digeneans of medical or economic importance. The effect of pollutants to the transmission of larval digeneans (miracidia, cercariae, metacercariae) and snail-digenean interactions is therefore considered. An overview and interpretation of the published literature on laboratory and field studies is provided. It is apparent from these studies that the influence of pollutants on digenean transmission is highly complex with much of the observed effects in the laboratory often masked by a complexity of other factors in the field. Future studies would benefit from a standardisation of experimental procedures, increasing the number of combined laboratory and field studies, and increasing the complexity of the experiments undertaken.

Type
Research Article
Copyright
© 2003 Cambridge University Press

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

ABD ALLAH, A. T., WANAS, M. Q. & THOMPSON, S. N. (1996). The effects of lead, cadmium, and mercury on the mortality and infectivity of Schistosoma mansoni cercariae. Journal of Parasitology 82, 10241026.CrossRefGoogle Scholar
ABD ALLAH, A. T., WANAS, M. Q. S. & THOMPSON, S. N. (1997). Effects of heavy metals on survival and growth of Biomphalaria glabrata Say (Gastropoda: Pulmonata) and interaction with Schistosome infection. Journal of Molluscan Studies 63, 7986.CrossRefGoogle Scholar
ABROUS, M., RONDELAUD, D. & DREYFUS, G. (2001). The stress of Lymnaea truncatula just before miracidial exposure with Fasciola hepatica increased the prevalence of infection. Experimental Parasitology 99, 4951.CrossRefGoogle Scholar
ADAM, M. E. & LEWIS, J. W. (1992). Sites of encystment by the metacercariae of Echinoparyphium recurvatum in Lymnaea peregra. Journal of Helminthology 66, 9699.CrossRefGoogle Scholar
ALBARET, J.-L. (1984). Comparaison des structures argyrophiles superficielles des miracidiums d'une douzaine d'especes du genre Schistosoma. Annales de Parasitologie Humaine et Comparee 59, 6377.CrossRefGoogle Scholar
ARME, C. (1988). Ontogenetic changes in helminth membrane function. Parasitology 96 (Suppl.), S83S104.CrossRefGoogle Scholar
ASCH, H. L. & DRESDEN, M. H. (1977). Schistosoma mansoni: Effect of zinc on cercarial and schistosomule viability. Journal of Parasitology 63, 8086.CrossRefGoogle Scholar
BEER, S. A. & GERMAN, S. M. (1993). [Ecological prerequisite for the worsening of the status of cercarioses in Russian towns (using the situation in the Moscow region as an example).] Parazitologiya 27, 441449. [IN RUSSIAN]Google Scholar
BEER, S. A. & GERMAN, S. M. (1994). [Ecological prerequisites for the distribution of schistosomatid dermatitis (cercariosis) in Moscow and its suburbs.] Meditsinskaya Parazitologiya i Parazitarnye Bolezni 1, 1619. [IN RUSSIAN]Google Scholar
BEER, S. A., STRUGOVA, A. S. & GERMAN, S. M. (1994). [Evaluation of the potential of aquatic biocoenoses for eliminating free-living forms of Opisthorchis felineus.] Parazitologiya 28, 458464. [IN RUSSIAN]Google Scholar
BONIECKA, B. & GUTTOWA, A. (1975). The influence of pesticides on the oxygen uptake by miracidia of Fasciola hepatica (Trematoda). Bulletin de L'Academie Polonaise des Sciences Biologiques 23, 463467.Google Scholar
BOOTH, G. H., Jr. & SCHULBERT, A. R. (1968). Zinc metabolism in schistosomes. Proceedings of the Society for Experimental Biology and Medicine 127, 700704.CrossRefGoogle Scholar
BRGLEZ, J. & WIKERHAUSER, T. (1968). On the effect of some fertilizers and copper sulphate upon the survival of cercariae and metacercariae of Fasciola hepatica. Wiadomosci Parazytologiczne 14, 675677.Google Scholar
BROWN, A. P. & PASCOE, D. ( 1989). Parasitism and host sensitivity to cadmium: an acanthocephalan infection of the freshwater amphipod Gammarus pulex. Journal of Applied Ecology 26, 473487.CrossRefGoogle Scholar
BRUAUX, P. & GILLET, J. (1961). Comparaison de l'activite de divers molluscicides en laboratoire. Bulletin of the World Health Organization 25, 519523.Google Scholar
BRYAN, G. W., GIBBS, P. E., BURT, G. R. & HUMMERSTONE, L. G. (1987). The effects of tributyltin (TBT) accumulation on adult dog-whelks, Nucella lapillus: long-term field and laboratory experiments. Journal of the Marine Biological Association of the United Kingdom 67, 525544.CrossRefGoogle Scholar
BRYAN, G. W., LANGSTON, W. J., HUMMERSTONE, L. G., BURT, G. R. & HO, Y. B. (1983). An assessment of the gastropod, Littorina littorea, as an indicator of heavy-metal contamination in United Kingdom estuaries. Journal of the Marine Biological Association of the United Kingdom 63, 327345.CrossRefGoogle Scholar
BUNNAG, T., DE FREITAS, J. R. & SCOTT, H. G. (1978). Sewage stabilization pond: the effects on Schistosoma mansoni transmission. Southeast Asian Journal of Tropical Medicine and Public Health 9, 4147.Google Scholar
BUSTNES, J. O. & GALAKTIONOV, K. V. (1999). Anthropogenic influences on the infestation of intertidal gastropods by seabird trematode larvae on the southern Barents Sea coast. Marine Biology 133, 449453.CrossRefGoogle Scholar
CANNING, E. U. (1982). An evaluation of protozoal characteristics in relation to biological control of pests. In Parasites as Biological Control Agents (ed. Anderson, R. M. & Canning, E. U.). Parasitology 84, 119149.CrossRef
CANNING, E. U., BARKER, R. J., HAMMOND, J. C. & NICHOLAS, J. P. (1983). Unikaryon slaptonleyi sp. nov. (Microspora: Unikaryonidae) isolated from echinostome and strigeid larvae from Lymnaea peregra: observations on its morphology, transmission and pathogenicity. Parasitology 87, 175184.Google Scholar
CHAIA, G. & PAULINI, E. (1957). Da acao do pentaclorofenato de sodio e do sulfato de cobre sobre ovos e miracidios se Schistosoma mansoni. Revista Brasileira de Malariologia e Doencas Tropicais 9, 511514.Google Scholar
CHERNOGORENKO, M. I. (1975). [On the life-span of free-living cercariae.] Parazity i parazitozy zhivotnykh i cheloveka. Kiev, USSR; 206211. [IN RUSSIAN]Google Scholar
CHERNOGORENKO, M. I. (1978). [The effect of “silver water” on the survival of Diplostomum spathaceum cercariae.] Problemy gidro-parazitologii. Kiev, USSR; 163165. [IN RUSSIAN]Google Scholar
CHERNOGORENKO, M. I. (1982). Periodicity, diurnal rhythm and ecologic factors influencing the rate of issuance of cercariae from mollusc hosts. Hydrobiological Journal 18(3), 6472.Google Scholar
CHRISTENSEN, N. O. (1979). Schistosoma mansoni: interference with cercarial host-finding by various aquatic organisms. Journal of Helminthology 53, 714.CrossRefGoogle Scholar
CHRISTIAN, F. A. & TATE, T. M. (1982). Effects of fluometuron on embryonic development and hatching of Fasciola hepatica's miracidia. Bulletin of Environmental Contamination and Toxicology 28, 353357.CrossRefGoogle Scholar
CHRISTIAN, F. A., TESFAMICHAEL, T. & TATE, T. (1985 a). Long-term effects of dinoseb and paraquat, both individually and combined, on embryonic development and hatching success of Fasciola hepatica miracidia. Archives of Environmental Contamination and Toxicology 14, 149152.Google Scholar
CHRISTIAN, F. A., TATE, T. M., TESFAMICHAEL, T. & LEBLANC, C. (1985 b). Effects of MSMA (Monosodium Methanearsonate) and Diuron on embryo development and hatching of Fasciola hepatica miracidia. Environmental Pollution 38, 17.Google Scholar
CROSS, M. A., IRWIN, S. W. B. & FITZPATRICK, S. M. (2001). Effects of heavy metal pollution on swimming and longevity in cercariae of Cryptocotyle lingua (Digenea: Heterophyidae). Parasitology 123, 499507.CrossRefGoogle Scholar
DAKUL, D. A., IYAGBA, A. O., AKUFONGWE, P. F. & OMOREGIE, E. (2000). Effects of inorganic fertilizers on the mortality of Schistosoma mansoni cercariae and their infectivity in the albino mice. Journal of Aquatic Sciences 15, 2729.CrossRefGoogle Scholar
DANSCHER, G. (1984). Autometallography. A new technique for light and electron microscopic visulization of metals in biological tissues (gold, silver, metal sulphides and metal selenides). Histochemistry 81, 331335.CrossRefGoogle Scholar
DANSCHER, G., RYTTER NORGAARD, J. O. & BAATRUP, E. (1987). Autometallography: Tissue metals demonstrated by a silver enhancement kit. Histochemistry 86, 465469.CrossRefGoogle Scholar
DEPLEDGE, M. H., WEEKS, J. M. & BJERREGAARD, P. (1994). Heavy Metals. In Handbook of Ecotoxicology (2 volumes) (ed. Callow, P.), pp. 79104. Oxford, Blackwell Scientific.
DRESDEN, M. H. & EDLIN, E. M. (1974). Schistosoma mansoni: Effect of some cations on the proteolytic enzymes of cercariae. Experimental Parasitology 35, 299303.CrossRefGoogle Scholar
DREYFUSS, G., VIGNOLES, P. & RONDELAUD, D. (2000). Variability of Fasciola hepatica infection in Lymnaea ovata in relation to snail population and snail age. Parasitology Research 86, 6973.CrossRefGoogle Scholar
EL-RIDI, A. M. S., EL-GINDY, M. S., ARAFA, M. S. & FARGHLY, A. M. (1983). Some factors affecting the hatchability of Schistosoma ova and miracidial activity. Journal of the Egyptian Society of Parasitology 13, 155159.Google Scholar
EVANS, D. W. (1995). The effect of trematode parasite larvae on the invertebrate fauna of Whitehouse Lagoon. D. Phil. thesis, University of Ulster, Northern Ireland.
EVANS, D. W., IRWIN, S. W. B. & FITZPATRICK, S. (2001). The effect of digenean (Platyhelminthes) infections on heavy metal concentrations in Littorina littorea. Journal of the Marine Biological Association of the United Kingdom 81, 349350.CrossRefGoogle Scholar
EVANS, N. A. (1982 a). Effect of copper and zinc upon the survival and infectivity of Echinoparyphium recurvatum cercariae. Parasitology 85, 295303.Google Scholar
EVANS, N. A. (1982 b). Effects of copper and zinc on the life cycle of Notocotylus attenuatus (Digenea: Notocotylidae). International Journal for Parasitology 12, 363369.Google Scholar
EVANS, S. M., KERRIGAN, E. & PALMER, N. (2000). Causes of imposex in the dogwelk, Nucella lapillus (L.) and its use as a biological indicator of tributyltin contamination. Marine Pollution Bulletin 40, 212219.Google Scholar
FAGBEMI, B. O. (1984). The effects of environmental factors on the development, behaviour and survival of Paramphistomum microbothrium miracidia. Veterinary Parasitology 16, 7181.CrossRefGoogle Scholar
FIELD, L. C. & IRWIN, S. W. B. (1999). Digenean larvae in Hydrobia ulvae from Belfast Lough (Northern Ireland) and the Ythan Estuary (north-east Scotland). Journal of the Marine Biological Association of the United Kingdom 79, 431435.CrossRefGoogle Scholar
FUSCO, A. C., SALAFSKY, B., VANDERKOOI, G. & SHIBUYA, T. (1991). Schistosoma mansoni: The role of calcium in the stimulation of cercarial proteinase release. Journal of Parasitology 77, 649657.CrossRefGoogle Scholar
GALAKTIONOV, K. V. (1996). Life cycles and distribution of seabird helminths in Arctic and sub-Arctic regions. Bulletin of the Scandinavian Society of Parasitology 6, 3149.Google Scholar
GALAKTIONOV, K. V. & BUSTNES, J. O. (1995). Species composition and prevalence of seabird trematode larvae in periwinkles at two littoral sites in North-Norway. Sarsia 80, 187191.CrossRefGoogle Scholar
GHANDOUR, A. M. & WEBBE, G. (1975). The effect of sublethal concentrations of the molluscide niclosamide on the infectivity of Schistosoma mansoni cercariae. Journal of Helminthology 49, 245250.CrossRefGoogle Scholar
GIBBS, P. E., BRYAN, G. W., PASCOE, P. L. & BURT, G. R. (1987). The use of the dog-whelk, Nucella lapillus, as an indicator of tributyltin (TBT) contamination. Journal of the Marine Biological Association of the United Kingdom 67, 507523.CrossRefGoogle Scholar
GUPTA, S. C. & KAMRA, D. N. (1987). Influence of wastelage fermentation on viability of Fasciola gigantica metacercariae. Biological Wastes 22, 311313.CrossRefGoogle Scholar
GUTH, D. J., BLANKESPOOR, H. D. & CAIRNS, Jr., J. (1977). Potentiation of zinc stress caused by parasitic infections of snails. Hydrobiologia 55, 225229.CrossRefGoogle Scholar
GUTTOWA, A. (1975). Toxicity of some pesticides to Helminth larvae. Bulletin de L'Academie Polonaise des Sciences Biologiques 23, 399404.Google Scholar
GUTTOWA, A. (1976). Effect of Methoxychlor on the embryonic development and respiratory metabolism of Fasciola hepatica (Trematoda) and Triaenophorous nodulosus (Cestoda) embryos. Bulletin de L'Academie Polonaise des Sciences Biologiques 24, 759764.Google Scholar
GUTTOWA, A. & BONIECKA, B. (1975). The effects of Foschlor and MCPA upon the embryo development of Fasciola hepatica (Trematoda) and Trianophorus nodulosus. Bulletin de L'Academie Polonaise des Sciences Biologiques 23, 391397.Google Scholar
GUTTOWA, A. & BONIECKA, B. (1977). The in vitro effects of organic phosphorus compounds and carbamates on development of Fasciola hepatica L. (Trematoda) and Triaenophorus nodulosus (pall.) (Cestoda) embryos. Acta Parasitologica Polonica 24, 315322.Google Scholar
GUTTOWA, A. & GRABIEC, S. (1974). Effect of chronic action of sublethal pesticide concentrations (sodium methyldithiocarbamate – VAPAM) on the metabolic activity of Fasciola hepatica (Trematoda) and Triaenophorus nodulosus (Cestoda) embryos. Bulletin de L'Academie Polonaise des Sciences Biologiques 22, 329334.Google Scholar
HALAWANI, A., LATIF, N. & TAHA, A. (1951). On pentabromophenol and pentachlorophenol as molluscicides in the prevention of bilharziasis. Journal of the Royal Egyptian Medical Association 34, 163170.Google Scholar
HARA, I., HARA, S., SALAFSKY, B. & SHIBUYA, T. (1993 a). Schistosoma mansoni: fatty acid-induced cercarial tail loss does not involve eicosanoid production and chemoreceptors. Experimental Parasitology 77, 484488.Google Scholar
HARA, I., HARA, S., FUSCO, A. C., SALAFSKY, B. & SHIBUYA, T. (1993 b). Role of calcium ion in Schistosoma mansoni cercarial tail loss induced by unsaturated fatty acids. Journal of Parasitology 79, 504509.Google Scholar
HARVELL, C. D., MITCHELL, C. E., WARD, J. R., ALTIZER, S., DOBSON, A. P., OSTFELD, R. S. & SAMUEL, M. D. (2002). Climate warming and disease risks for terrestrial and marine biota. Science 296, 21582162.CrossRefGoogle Scholar
HEINONEN, J., KUKKONEN, J. V. K. & HOLOPAINEN, I. J. (1999). The effects of parasites and temperature on the accumulation of xenobiotics in a freshwater clam. Ecological Applications 9, 475481.CrossRefGoogle Scholar
HEINONEN, J., KUKKONEN, J. V. K. & HOLOPAINEN, I. J. (2000). Toxiceokinetics of 2,4,5-trichlorophenol and benzo(a)pyrene in the clam Pisidium amnicum: Effects of seasonal temperatures and trematode parasites. Archives of Environmental Contamination and Toxicology 39, 352359.CrossRefGoogle Scholar
HEINONEN, J., KUKKONEN, J. V. K. & HOLOPAINEN, I. J. (2001). Temperature- and parasite-induced changes in toxicity and lethal body burdens of pentachlorophenol in the freshwater clam Pisidium amnicum. Environmental Toxicology and Chemistry 20, 27782784.CrossRefGoogle Scholar
HEINONEN, J., PENTTINEN, O.-P., HOLOPAINEN, I. J. & KUKKONEN, J. V. K. (2003). Sublethal energetic responses by Pisidium amnicum (Bivalvia) exposed to Pentachlorophenol at two temperatures. Environmental Toxicology and Chemistry 22, 433438.CrossRefGoogle Scholar
HELLAWELL, J. M. (1986). Biological Indicators of Freshwater Pollution and Environmental Management. London, Elsevier Applied Science Publishers.CrossRef
HIRA, P. R. & WEBBE, G. (1972). The effect of sublethal concentrations of the molluscide Triphenyl Lead Acetate on Biomphalaria glabrata (Say) and on the development of Schistosoma mansoni in the snail. Journal of Helminthology 46, 1126.Google Scholar
HMSO (1969). Fish toxicity tests. Her Majesty's Stationary Office Leaflet, No. Dd. 139779 K36 12/69.
HOFF, C. C. (1941). A case of correlation between infection of snail hosts with Cryptocotyle lingua and the habitats of gulls. Journal of Parasitology 27, 539.CrossRefGoogle Scholar
HOLLIMAN, R. B. & ESHAM, L. P. (1977). Toxicity of cadmium to Schistosoma mansoni cercariae: Effects on vitality and developmental ability in white mice. Hydrobiologia 56, 8188.CrossRefGoogle Scholar
HOWE, D. K. & NOLLEN, P. M. (1992). The effects of pH and salinity on the behavior of Philophthalmus gralli (Trematoda) miracidia. Transactions of the Illinois State Academy of Science 85, 7377.Google Scholar
HSU, H. H. (1986). The uptake and distribution of radioselenium in the larvae of Fasciola hepatica and its snail host Lymnaea columella. Veterinary Parasitology 21, 233245.CrossRefGoogle Scholar
IBRAHIM, W. L. F., FURU, P., IBRAHIM, A. M. & CHRISTENSEN, N. O. (1992). Effect of the organophosphorous insecticide, chlorpyrifos (Dursban), on growth, fecundity and mortality of Biomphalaria alexandrina and on the production of Schistosoma mansoni cercariae in the snail. Journal of Helminthology 66, 7988.CrossRefGoogle Scholar
IGBINOSA, I. B. & OKAFOR, F. C. (1988). Environmental stress and parasitic infections: I. The effects of Gramoxone and Hexadrin on embryo and hatching of Fasciola gigantica miracidia. Angewandte Parasitologie 29, 179183.Google Scholar
KHAN, R. A. & THULIN, J. (1991). Influence of pollution on parasites of aquatic animals. Advances in Parasitology 30, 201238.CrossRefGoogle Scholar
KIESECKER, J. M. (2002). Synergism between trematode infection and pesticide exposure: A link to amphibian limb deformities in nature? Proceedings of the National Academy of Science, USA 99, 99009904.Google Scholar
KING, C. L. & HIGASHI, G. I. (1992). Schistosoma mansoni: Silver ion (Ag+) stimulates and reversibly inhibits lipid-induced cercarial penetration. Experimental Parasitology 75, 3139.CrossRefGoogle Scholar
KNIGHT, W. B., LIARD, F., RITCHIE, L. S., PELLEGRINO, J. & CHIRIBOGA, J. (1968). Labeling of Biomphalaria glabrata and cercariae of Schistosoma mansoni with radioselenium. Experimental Parasitology 22, 309315.CrossRefGoogle Scholar
KORNER, M. & HAAS, W. (1998). Chemo-orientation of echinostome cercariae towards their snail hosts: amino acids signal a low host-specificity. International Journal for Parasitology 28, 511516.CrossRefGoogle Scholar
KRAAK, M. H. S. & DAVIDS, C. (1991). The effect of the parasite Phyllodistomum macrocotyle (trematoda) on heavy metal concentrations in the freshwater mussel Dreissena polymorpha. Netherlands Journal of Zoology 41, 269276.Google Scholar
KRUPICER, I., VELEBNY, S. & LEGATH, J. (1996). [Effect of emissions from a mercury treating metallurgical works on the intensity of experimental Fasciola hepatica infection in sheep.] Veterinarni Medicina 41, 103106. [IN SLOVAKIAN]Google Scholar
KUNTZ, R. E. & STIREWALT, M. A. (1946). Effects of DDT on cercariae of Schistosoma mansoni. Journal of Parasitology 32, 529538.CrossRefGoogle Scholar
LAFFERTY, K. D. (1997). Environmental parasitology: what can parasites tell us about human impacts on the environment? Parasitology Today 13, 251255.Google Scholar
LAFFERTY, K. D. & KURIS, A. M. (1999). How environmental stress affects the impacts of parasites. Limnology and Oceanography 44, 925931.CrossRefGoogle Scholar
LAUCKNER, G. (1980). Diseases of Mollusca: Gastropoda. In Diseases of Marine Animals (ed. Kinne, O.), Vol. I, pp. 311424. Hamburg, Biologishe Anstalt Helgoland.
LAUCKNER, G. (1985). Diseases of Aves (marine birds). In Diseases of Marine Animals (ed. Kinne, O.), Vol. IV, pp. 627643. Hamburg, Biologishe Anstalt Helgoland.
LAVRIK, V. I., DAVIDOV, O. N. & BRAGINSKIY, L. P. (2000). Some conceptual approaches to modeling the ‘Parasite-Host’ system under conditions of toxically contaminated aquatic environment. Hydrobiological Journal 36(2), 121128.CrossRefGoogle Scholar
LAWSON, J. R. & WILSON, R. A. (1983). The relationship between the age of Schistosoma mansoni cercariae and their ability to penetrate and infect the mammalian host. Parasitology 87, 481492.CrossRefGoogle Scholar
LEFCORT, H., AGUON, M. Q., BOND, K. A., CHAPMAN, K. R., CHAQUETTE, R., CLARK, J., KORNACHUK, P., LANG, B. Z. & MARTIN, J. C. (2002). Indirect effects of heavy metals on parasites may cause shifts in snail species compositions. Archives of Environmental Contamination and Toxicology 43, 3441.CrossRefGoogle Scholar
LEWERT, R. M., HOPKINS, D. R. & MANDLOWITZ, S. (1966). The role of calcium and magnesium ions in invasiveness of schistosome cercariae. American Journal of Tropical Medicine and Hygiene 15, 314323.CrossRefGoogle Scholar
LEWERT, R. M. & LEE, C. (1956). Quantitative studies of the collagnase-like enzymes of cercariae of Schistosoma mansoni and the larvae of Strongyloides ratti. Journal of Infectious Diseases 99, 114.Google Scholar
LWAMBO, N. J. S., UPATHAM, E. S., KRUATRACHUE, M. & VIYANANT, V. (1987). The host-parasite relationship between the Saudi Arabian Schistosoma mansoni and its intermediate and definitive hosts. 2. Effects of temperature, salinity and pH on the infection of mice by S. mansoni cercariae. Southeast Asian Journal of Tropical Medicine and Public Health 18, 166170.Google Scholar
MACKENZIE, K. (1999). Parasites as pollution indicators in marine ecosystems: a proposed early warning system. Marine Pollution Bulletin 38, 955959.CrossRefGoogle Scholar
MACKENZIE, K., WILLIAMS, H. H., WILLIAMS, B., McVICAR, A. H. & SIDDALL, R. (1995). Parasites as indicators of water quality and the potential use of helminth transmission in marine pollution studies. Advances in Parasitology 35, 85144.CrossRefGoogle Scholar
MARCOGLIESE, D. J. (2001). Implications of climate change for parasitism of animals in the aquatic environment. Canadian Journal of Zoology 79, 13311352.CrossRefGoogle Scholar
MASSOUD, J., ARFAA, F. & CHU, K. Y. (1973). Effect of Bayluscide (Bayer-73) on the development of Schistosoma haematobium in Bulinus truncatus. Bulletin de la Société de Pathologie Exotique 66, 544547.Google Scholar
MASSOUD, J. & WEBBE, G. (1969). The effect of sub-lethal doses of the molluscide (N-tritylmorpholine) on the development of Schistosoma mansoni in Biomphalaria glabrata (Say). Journal of Helminthology 43, 99110.CrossRefGoogle Scholar
MATTHEWS, P. M., MONTGOMERY, W. I. & HANNA, R. E. B. (1985). Infestation of littorinids by larval Digenea around a small fishing port. Parasitology 90, 277287.CrossRefGoogle Scholar
MATSUMURA, K., MITSUI, Y., SATO, K., SAKAMOTO, M. & AODI, Y. (1991). Schistosoma mansoni: Possible involvement of protein kinase C in linoleic acid-induced proteolytic enzyme release from cercariae. Experimental Parasitology 72, 311320.CrossRefGoogle Scholar
MECHAM, J. A. & HOLLIMAN, R. B. (1975). Toxicity of zinc to Schistosoma mansoni cercariae in a chemically defined water medium. Hydrobiologia 46, 391404.CrossRefGoogle Scholar
MICHAJLOW, W. & WITA, I. (1976). Effect of VAPAM – a pesticide of the carbamate group – on Ergasilus sieboldi Nordmann (Copepoda) a parasite of the pike and on Paradistigma triangulatum Wita (Euglenoidina) a parasite of this Copepod. Bulletin de L'Academie Polonaise des Sciences Biologiques 24, 113116.Google Scholar
MIMPFOUNDI, R. & DUPOUY, J. (1983). Action de certains detergents en usage au Cameroun sur la vitalite des cercaires de Schistosoma mansoni: influence du facteur durete de l'eau (dH). Comptes Rendeus des Seances – Societe de Biologie et de ses Filiales 177, 338347.Google Scholar
MISECHKO, L. E. & STADNICHENKO, A. P. (1988). [Intoxication of Lymnaea stagnalis infected by trematode parthenits with copper sulphate.] Parazitologiya 22, 9699. [IN RUSSIAN]Google Scholar
MOCZON, T. (1976 a). Influence of pesticides on the activities of some oxidoreductases in the miracidia of Fasciola hepatica. Histochemical data. Bulletin de L'Academie Polonaise des Sciences Biologiques 24, 227231.Google Scholar
MOCZON, T. (1976 b). Inhibitory effect of pesticides on phosphatase, glucosidase and acetylcholinesterase activity in miracidia of Fasciola hepatica. Histochemical data. Bulletin de L'Academie Polonaise des Sciences Biologiques 24, 289292.Google Scholar
MOHAMED, A. M., EL FIKI, S. A., EL SAWY, M. F. & EL WAKIL, H. (1981). Effect of prolonged exposure of Biomphalaria alexandrina to low concentrations of some molluscides. I. Effects on longevity, growth rate, fecundity and susceptability to schistosome infection. Journal of the Egyptian Society of Parasitology 11, 295311.Google Scholar
MORLEY, N. J., CRANE, M. & LEWIS, J. W. (2001 a). Toxicity of cadmium and zinc to miracidia of Schistosoma mansoni. Parasitology 122, 8185.Google Scholar
MORLEY, N. J., CRANE, M. & LEWIS, J. W. (2001 b). Toxicity of cadmium and zinc to encystment and in vitro excystment of Parorchis acanthus (Digenea: Philophthalmidae). Parasitology 122, 7579.Google Scholar
MORLEY, N. J., CRANE, M. & LEWIS, J. W. (2001 c). Toxicity of cadmium and zinc to Diplostomum spathaceum (Trematoda: Diplostomidae) cercarial survival. International Journal for Parasitology 31, 12111217.Google Scholar
MORLEY, N. J., CRANE, M. & LEWIS, J. W. (2002 a). Toxic effects of cadmium and zinc on the transmission of Echinoparyphium recurvatum cercariae. Journal of Helminthology 76, 157163.Google Scholar
MORLEY, N. J., CRANE, M. & LEWIS, J. W. (2002 b). Toxicity of cadmium and zinc mixtures to Diplostomum spathaceum (Trematoda: Diplostomidae) cercarial survival. Archives of Environmental Contamination and Toxicology 43, 2833.Google Scholar
MORLEY, N. J., CRANE, M. & LEWIS, J. W. (2002 c). Toxicity of cadmium and zinc to cercarial tail loss in Diplostomum spathaceum (Trematoda: Diplostomidae). Parasitology 125, 293301.Google Scholar
MORLEY, N. J., CRANE, M. & LEWIS, J. W. (2002 d). Toxicity of cadmium and zinc to encystment of Notocotylus attenuatus (Trematoda: Notocotylidae) cercariae. Ecotoxicology and Environmental Safety 53, 129133.Google Scholar
MORLEY, N. J., CRANE, M. & LEWIS, J. W. (2003 a). Cadmium toxicity and snail-digenean interactions in a population of Lymnaea spp. (Gastropoda: Pulmonata). Journal of Helminthology 77, 4955.Google Scholar
MORLEY, N. J., CRANE, M. & LEWIS, J. W. (2003 b). Toxicity of cadmium and zinc to the cercarial activity of Diplostomum spathaceum (Trematoda: Diplostomidae). Folia Parasitologica 50, 5760.Google Scholar
MORLEY, N. J., CRANE, M. & LEWIS, J. W. (2003 c). Effects of cadmium and zinc toxicity on orientation behaviour of Echinoparyphium recurvatum (Digenea: Echinostomatidae) cercariae. Diseases of Aquatic Organisms (in press).Google Scholar
MORLEY, N. J., LEUNG, K. M. Y., MORRITT, D. & CRANE, M. (2003 d). Toxicity of anti-fouling biocides to Parorchis acanthus (Digenea: Philophthalmidae) cercarial encystment. Diseases of Aquatic Organisms 54, 5560.Google Scholar
MOURITSEN, K. N. & POULIN, R. (2002). Parasitism, climate oscillations and the structure of natural communities. Oikos 97, 462468.CrossRefGoogle Scholar
MOUSA, A. H., YOUSIF, F. & EL-GHAYEB, F. M. (1970). Studies on low concentrations of molluscides. II. Effect of low concentrations of molluscides on the survival and infectivity of Schistosoma mansoni cercariae. Bulletin of the Zoological Society of Egypt 23, 6573.Google Scholar
NOLLEN, P. M., SAMIZADEH-YAZD, A. & SNYDER, D. E. (1979). The longevity and hatchability of Philophthalmus megalurus and P. gralli miracidia in different environmental conditions. Journal of Parasitology 65, 772776.Google Scholar
OKAFOR, F. C. & IGBINOSA, I. B. (1988). Environmental stress and parasitic infections: II. Effects of Gramoxone and Hexadrin (pesticides) on the survival characteristics of Fasciola gigantica miracidia. Angewandte Parasitologie 29, 221225.Google Scholar
OSHIMA, T., KITAGUCHI, T., SAITO, K. & KANAYAMA, A. (1992). [Studies on the epidemiology of avian schistosome dermatitis caused by the cercariae of Gigantobilharzia sturniae.] Japenese Journal of Parasitology 41, 194201. [IN JAPANESE]Google Scholar
PIETROCK, M., MARCOGLIESE, D. J. & McLAUGHLIN, J. D. (2002 a). Effect of cadmium upon longevity of Diplostomum sp. (Trematoda: Diplostomidae) cercariae. Chemosphere 47, 2933.Google Scholar
PIETROCK, M., MARCOGLIESE, D. J., MEINELT, T. & McLAUGHLIN, J. D. (2002 b). Effects of mercury and chromium upon longevity of Diplostomum sp. (Trematoda: Diplostomidae) cercariae. Parasitology Research 88, 225229.Google Scholar
PIETROCK, M., MEINELT, T., MARCOGLIESE, D. J. & STEINBERG, C. E. W. (2001). Influence of aqueous sediment extracts from the Oder River (Germany/Poland) on survival of Diplostomum sp. (Trematoda: Diplostomidae) cercariae. Archives of Environmental Contamination and Toxicology 40, 327332.Google Scholar
POULIN, R. (1992). Toxic pollution and parasitism in freshwater fish. Parasitology Today 8, 5861.CrossRefGoogle Scholar
PRESING, M., BALOGH, K. V. & SALANKI, J. (1993). Cadmium uptake and depuration in different organs of Lymnaea stagnalis L. and the effect of cadmium on natural zinc levels. Archives of Environmental Contamination and Toxicology 24, 2834.CrossRefGoogle Scholar
RAMAJO-MARTIN, V. & MARTIN, V. R. (1979). [Effect of temperature and pH on the survival and activity of Schistosoma bovis miracidia.] Revista Iberica de Parasitologia 39, 251260. [IN SPANISH]Google Scholar
RITCHIE, L. S., LOREZ, V. A. & CORA, J. M. (1974). Prolonged application of an organotin against Biomphalaria glabrata and schistosomiasis control In Molluscides in Schistosomiasis Control (ed. Cheng, T. C.), pp. 7788. New York, Academic Press.
RONDELAUD, R. (1995). The characteristics of redial generations in Lymnaea truncatula exposed to Fasciola hepatica miracidia after poisoning by sublethal doses of cupric chloride. Veterinary Research 26, 2126.Google Scholar
SALICE, C. J. & ROESIJADI, G. (2002). Resistance to cadmium and parasite infection are inversely related in two strains of a freshwater gastropod. Environmental Toxicology & Chemistry 21, 13981403.CrossRefGoogle Scholar
SANKURATHRI, C. S. & HOLMES, J. C. (1976). Effects of thermal effluents on parasites and commensals of Physa gyrina Say (Mollusca: Gastropoda) and their interactions at Lake Wabamun, Alberta. Canadian Journal of Zoology 54, 17421753.CrossRefGoogle Scholar
SHARIFI, I. & NOLLEN, P. M. (1981). The effects of six herbicides on the longevity of Schistosoma mansoni miracidia. Transactions of the Illinois State Academy of Science 74, 9197.Google Scholar
SIDDALL, R. (1992). Parasites as biological indicators of sewage sludge dispersal. PhD thesis, University of Aberdeen.
SIDDALL, R. & DES CLERS, S. (1994). Effects of sewage sludge on the miracidium and cercariae of Zoogonoides viviparus (Trematoda:Digenea). Helminthologia 31, 143153.Google Scholar
SIDDALL, R., PIKE, A. W. & McVICAR, A. H. (1993). Parasites of Buccinum undatum (Mollusca: Prosobranchia) as biological indicators of sewage-sludge dispersal. Journal of the Marine Biological Association of the United Kingdom 73, 931948.CrossRefGoogle Scholar
SIDDALL, R., PIKE, A. W. & McVICAR, A. H. (1994). Parasites of flatfish in relation to sewage sludge dumping. Journal of Fish Biology 45, 193209.CrossRefGoogle Scholar
SIDDALL, R. & SURES, B. (1998). Uptake of lead by Pomphorhynchus laevis cystacanths in Gammarus pulex and immature worms in Chub (Leuciscus cephalus). Parasitology Research 84, 573577.CrossRefGoogle Scholar
SMITH, G. & GRENFELL, B. T. (1984). The influence of water temperature and pH on the survival of Fasciola hepatica miracidia. Parasitology 88, 97104.CrossRefGoogle Scholar
SOH, C.-T., KIM, C.-W., AHN, Y.-K. & CHUNG, Y. (1980). Environmental studies of the snail, Parafossarulus manchouricus, along Yeongsan River in Korea. Yonsei Reports on Tropical Medicine 11(1), 113.Google Scholar
SOUCEK, D. J. & NOBLET, G. P. (1998). Copper toxicity to the endoparasitic trematode (Posthodiplostomum minimum) relative to physid snail and bluegill sunfish intermediate hosts. Environmental Toxicology and Chemistry 17, 25122516.CrossRefGoogle Scholar
SOUS, S. M. (1992). Influence of abiotic factors on emission and survival of cercariae of Diplostomum chromatophorum (Brown, 1931) (Trematoda, Diplostomidae). Ecological Parasitology 1, 154159.Google Scholar
STADNICHENKO, A. P., ANISTRATENKO, V. V., GRABINSKAYA, O. V., MARTYNYUK, O. V., MIROSHNICHENKO, O. A., OLEINIK, N. G., SERGEICHUK, S. A. & FASOLYA, O. I. (1994). [Infection of unionids (Mollusca: Bivavia: Unionidae) with parthenitae of Bucephalus polymorphus (trematoda) and effect of the parasites on the cardiac rhythm of the host.] Parazitologiya 28, 124130. [IN RUSSIAN]Google Scholar
STADNICHENKO, A. P. & GOLOVACHEVA, L. D. (1990). [The influence of different concentrations of surfactants on the physical and chemical properties of the haemolymph of Planorbarius (Mollusca, Bulinidae) infected with trematodes and free from infection.] Parazitologiya 24, 238242. [IN RUSSIAN]Google Scholar
STADNICHENKO, A. P., IVANENKO, L. D., DRASIK, I. A., KOVALCHUK, A. N., NIKITYUK, M. M. & YAVORSKAYA, Z. M. (1996 a). [Influence of different magnesium sulphate concentrations on physical and chemical characteristics of Planorbarius haemolymph (Mollusca: Bulinidae) in a normal state and under trematode infection.] Parazitologiya 30, 244249. [IN RUSSIAN]Google Scholar
STADNICHENKO, A. P., IVANENKO, L. D., GORCHENKO, I. S., GRABINSKAYA, O. V., OSADCHUK, L. A. & SERGEJCHUK, S. A. (1995). [The effect of different concentrations of the sulphate nickel on the horn snail (Mollusca: Bulinidae) infected with the trematode Cotylurus cornutus (Strigeidae).] Parazitologiya 29, 112116. [IN RUSSIAN]Google Scholar
STADNICHENKO, A. P., IVANENKO, L. D., GUSENKO, O. V., SVITEL'SKY, N. M. & SYCHEVSKY, A. S. (1996 b). [Influence of joint affect of trematode infection, environmental temperature and lead nitrate on lung and skin transpirations in a pond snail (Pulmonata: Lymnaeidae).] Parazitologiya 30, 515520. [IN RUSSIAN]Google Scholar
STADNICHENKO, A. P., IVANENKO, L. D., KURKCHI, L. N., VITKOVSKAYA, O. V., KALININA, N. N., VYSKUSHENKO, D. A. & SHEVCHUK, A. V. (1998). [Influence of trematode infection on accumilation of metal ions by freshwater molluscs (Gastropoda: Pulmonata: Pectinibranchia).] Parazitologiya 32, 357362. [IN RUSSIAN]Google Scholar
STADNICHENKO, A. P., IVANENKO, L. D., KURKCHI, L. N., VYSKUSHENKO, D. A., GRADOVSKAYA, R. P. & ZIMOVETZ, I. A. (1999 a). [Influence of Natrium and potassium chlorides on fast behavioural and physiological reactions of pond snails (Mollusca: Gastropoda: Pulmonata) under infection with trematode parthenites.] Parazitologiya 33, 335339.Google Scholar
STADNICHENKO, A. P., IVANENKO, L. D., KIRICHUK, G. E. & YANOVICH, L. M. (2001). [Influence of ferric chloride (III) on haematological indices of Planorbarius corneus (Mollusca: Gastropoda: Bulinidae) in normal snails and ones infected with trematode parthenites.] Parazitologiya 35, 109113. [IN RUSSIAN]Google Scholar
STADNICHENKO, A. P., IVANENKO, L. D. & SITNYAKOVSKAYA, A. M. (1987). [The effect of phenol and pesticides on the physiochemical properties of the haemolymph of freshwater gastropods infected with trematode parthenitae.] Parazitologiya 21, 716720. [IN RUSSIAN]Google Scholar
STADNICHENKO, A. P., IVANENKO, L. D., SLASTENKO, N. N., KIRICHUK, G. E., ANTONYUK, D. A., BARANYUK, R. S., KRIZSKAYA, E. V., MOSHKOVSKAYA, T. A. & RADKEVICH, O. S. (1999 b). [Influence of ammonium nitrate on physical and chemical characteristics of haemolymph of the flat-coil Planorbarius corneus (Mollusca: Bulinidae) infected with trematodes (Echinostomatidae).] Parazitologiya 33, 2631. [IN RUSSIAN]Google Scholar
STANICHENKO, A. P., IVANENKO, L. D., VASILENKO, O. F., VISHNEVSKAYA, A. YE., ZINICH, M. M., KIRICHUK, G. YE., MYSLINSKAYA, L. N. & SEMENIJ, T. A. (1993). [Trematode invasion and zinc sulphate impact upon physics-chemical properties of haemolymph of coil-flats (Mollusca: Bulinidae).] Parazitologiya 27, 404409. [IN RUSSIAN]Google Scholar
STADNICHENKO, A. P. & KIRICHUK, G. E. (2000). [The effect of ammonium nitrate on residual nitrogen content in the haemolymph of Planorbarius purpura (Mollusca: Pulmonata: Bulinidae) in normal and trematode-infected individuals.] Parazitologiya 34, 402407. [IN RUSSIAN]Google Scholar
STADNICHENKO, A. P. & KOTSYUK, R. V. (1990). [Influence of different concentrations of surface-active substances on the daily food intake and duration of the digestive process in Lymnaea stagnalis infected with Echinostoma revolutum parthenitae.] Parazitologiya 24, 528532. [IN RUSSIAN]Google Scholar
STADNICHENKO, A. P., MISECHKO, L. E. & SHEPEL, A. N. (1985). [Effect of phenol poisoning on the cartinoid pigment contents in the haemolymph of freshwater molluscs (Pulmonata, Lymnaeidae and Bulinidae) infected or uninfected with trematode parthenitae.] Parazitologiya 19, 101104. [IN RUSSIAN]Google Scholar
STADNICHENKO, A. P., POGORELOVA, N. S. & RUDENKO, S. A. (1991). [Effect of different concentrations of hydroquinone on Planorbarius corneus (Gastropoda, Pulmonata, Bulinidae) infected with parthenites of Tylodelphis excavata (Trematoda: Diplostomatidae).] Parazitologiya 25, 462467. [IN RUSSIAN]Google Scholar
STANICHENKO, A. P., SHABROVETS, T. I. & KOZAKIEVITCH, N. N. (1986). [Effect of cuprous sulphate solutions on ascorbic acid content in haemolymph of freshwater molluscs (Gastropda, Pulmonata) in normal conditions and during trematode infection.] Parazitologiya 20, 221224. [IN RUSSIAN]Google Scholar
STADNICHENKO, A. P., SLASTENKO, N. N., GUZENKO, O. V., SVITEL'SKY, N. M. & SYCHEVSKII, A. S. (1996 c). [Effect of trematode invasion and of the action of lead nitrate on the pulmonary and cutaneous respiration of Lymnaea stagnalis (Mollusca: Lymnaeidae).] Parazitologiya 30, 7680. [IN RUSSIAN]Google Scholar
STANICHENKO, A. P., SLASTENKO, N. N., KURKCHI, L. N., TOMASHEVSKAYA, I. A. & YANAKI, YE. A. (1992). [Trematode invasion and lead nitrate impact upon lung and dermal breath of coil-flats.] Parazitologiya 26, 6771. [IN RUSSIAN]Google Scholar
STADNICHENKO, A. P., ZELINSKAYA, A. YU., KRAVCHUK, A. D. & DOROSHENKO, G. V. (1988). [Effect of nitroammophoska solutions on aldolase activity in the haemolymph of the mollusc Planorbarius banaticus in the presence and absence of trematode infection.] Parazitologiya 22, 394397. [IN RUSSIAN]Google Scholar
STPICZYNSKA, R., RZECZKOWSKA, A. & GUTTOWA, A. (1978). The influence of pesticides on the invasive activity of miracidia and the asexual reproduction of Fasciola hepatica (Trematoda) larvae in the host snails. Bulletin de L'Academie Polonaise des Sciences Biologiques 26, 405410.Google Scholar
STRAIN, L. C. (1995). An investigation of the trematode parasites in the mud snail Hydrobia ulvae from sites of ornithological importance. D. Phil. thesis, University of Ulster, Northern Ireland.
STURROCK, R. F. (1993). The parasites and their life cycles. In Human Schistosomiasis (ed. Jordan, P., Webbe, G. & Sturrock, R. F.), pp. 132. Wallingford, CAB International.
SULLIVAN, J. T. & PALMIERI, J. R. (1979). Effect of duration and intensity of infection with Echinostoma audyi on survival of Lymnaea rubiginosa exposed to copper sulphate. Journal of Parasitology 65, 5054.CrossRefGoogle Scholar
SURES, B. & TARASCHEWSKI, H. (1995). Cadmium concentrations of two adult acanthocephalans (Pomphorhynchus laevis, Acanthocephalus lucii) compared to their fish hosts and cadmium and lead levels in larvae of A. lucii compared to their crustacean host. Parasitology Research 81, 494497.Google Scholar
TCHOUNWOU, P. B., ENGLANDE, Jr., A. J., MALEK, E. A., ANDERSON, A. C. & ABDELGHANI, A. A. (1991 a). The effects of Bayluscide and Malathion on the survival of Schistosoma mansoni miracidia. Journal of Environmental Science and Health Part B – Pesticides, Food, Contaminants and Agricultural Health 26, 6982.Google Scholar
TCHOUNWOU, P. B., ENGLANDE, Jr., A. J., MALEK, E. A., ANDERSON, A. C. & ABDELGHANI, A. A. (1991 b). The effects of ammonium sulphate and urea upon egg hatching and miracidial survival of Schistosoma mansoni. Journal of Environmental Science and Health Part B – Pesticides, Food, Contaminants and Agricultural Health 26, 241257.Google Scholar
TCHOUNWOU, P. B., ENGLANDE, Jr., A. J. & MALEK, E. A. (1992 a). The influence of selected environmental parameters on the toxicity of Bayluscide to Schistosoma mansoni miracidia. Archives of Environmental Contamination and Toxicology 23, 223229.Google Scholar
TCHOUNWOU, P. B., ENGLANDE, Jr., A. J. & MALEK, E. A., GREER, G. J. & ANDERSON, A. C. (1992 b). The effects of bayluscide and malathion on the mortality and infectivity of Schistosoma mansoni cercariae. Environmental Toxicology and Water Quality 7, 107117.Google Scholar
UGLEM, G. (1980). Sugar transport by larval and adult Proterometra macrostoma in relation to environmental factors. Journal of Parasitology 66, 748758.CrossRefGoogle Scholar
UPATHAM, E. S. (1972). Effects of some physio-chemical factors on the infection of Biomphalaria glabrata (Say) by miracidia of Schistosoma mansoni Sambon in St. Lucia, West Indies. Journal of Helminthology 46, 307315.Google Scholar
VIYANANT, V., THIRACHANTRA, S. & SORNMANI, S. (1982 a). The effects of controlled release copper sulphate and tributyltin fluoride on the mortality and infectivity of Schistosoma mansoni miracidia. Southeast Asian Journal of Tropical Medicine and Public Health 13, 225230.Google Scholar
VIYANANT, V., THIRACHANTRA, S. & SORNMANI, S. (1982 b). The effect of controlled release copper sulphate and tributyltin fluoride on the mortality and infectivity of Schistosoma mansoni cercariae. Journal of Helminthology 56, 8592.Google Scholar
VYSKUSHENKO, D. A. (2001). [Influence of copper sulphate on Lymnaea stagnalis heart rate (Mollusca: Gastropoda: Pulmonata) under infection with trematode parthenites.] Parazitologiya 35, 320324. [IN RUSSIAN]Google Scholar
WANAS, M. Q. A., THOMPSON, S. N. & ABD ALLAH, A. T. (1998). Effects of lead, mercury and cadmium on the extramolluscan larval stages of Schistosoma mansoni (Sambon). Journal of the Egyptian Society of Parasitology 28(2), 583594.Google Scholar
WAWRZYNIAK, U. (1992). [Effect of cadmium on the intestinal and muscle phase of Trichinella spiralis in mice.] Wiadomosci Parazytologiczne 38, 109115. [IN POLISH]Google Scholar
WHYTE, S. K., SECOMBES, C. J. & CHAPPELL, L. H. (1991). Studies on the infectivity of Diplostomum spathaceum in rainbow trout (Oncorhynchus mykiss). Journal of Helminthology 65, 169178.CrossRefGoogle Scholar
WOLMARANS, C. T., YSSEL, E. & HAMILTON-ATTWELL, V. L. (1988). Toxic effects of chromium on Schistosoma haematobium miracidia. Bulletin of Environmental Contamination and Toxicology 41, 928935.CrossRefGoogle Scholar
YESCOTT, R. E. & HANSEN, E. L. (1976). Effect of manganese on Biomphalaria glabata infected with Schistosoma mansoni. Journal of Invertebrate Pathology 28, 315320.CrossRefGoogle Scholar