Martorelli, S.R. (1994) A new cystophorous cercaria (Digenea, Hemiuriformes) in
Potamolithus agapetus(Mollusca, Hydrobiidae): behaviour of host attraction.
Iheringia Serie Zoologia0(77), 15–19.
Mohandas, A. and Nadakal, A.M. (1978)In vivodevelopment ofEchinostoma
malayanumLeiper 1911 with notes on effects of population density, chemical
composition and pathogenicity andin vitroexcystment of the metacercaria
(Trematoda: Echinostomatidae).Zeitschrift für Parasitenkunde55, 139–151.
Nassi, H., Pointier, J.P. and Golvan, Y.J. (1979) Bilan d’un essai de contrôle
deBiomphalaria glabrataen Guadalupe à l’aide d’un trématode stérilisant.
Annales de Parasitologie52, 277–323.
Noda, S. and Loker, E.S. (1989) Effects of infection withEchinostoma paraenseion
the circulating haemocyte population of the host snailBiomphalaria glabrata.
Parasitology98, 35–41.
Nolf, L. and Court, W.W. (1933) On immunity reactions of snails to the penetration
of the cercariae of the strigeid trematode,Cotylurus flabelliformis.Journal of
Parasitology20, 38–48.
Nollen, P.M. (1994) The hatching behavior ofEchinostoma trivolvismiracidia
and their responses to gravity, light and chemicals.International Journal for
Parasitology24, 637–642.
Olivier, L.J. (1966) Infectivity ofSchistosoma mansoni cercariae. American
Journal of Tropical Medicine and Hygiene15, 882–885.
Polis, G.A., Myers, C.A. and Holt, R.D. (1989) The ecology and evolution
of intraguild predation: potential competitors that eat each other.Annual
Review of Ecology and Systematics20, 292–330.
Rigby, M.C. and Jokela, J. (2000) Costs and trade-offs between predator avoidance
and immune defense in snails.Proceedings of the Royal Academy of London
B267, 171–176.
Riley, E.M. and Chappell, L.H. (1992) Effect of infection withDiplostomum
spathaceumon the internal defense system ofLymnaea stagnalis.Journal of
Invertebrate Pathology59, 190–196.
Robson, E.M. and Williams, I.C. (1970) Relationships of some species of Digenea
with the marine prosobranchLittorina littorea(L.) I. The occurrence of larval
Digenea inL. littoreaon the North Yorkshire Coast.Journal of Helminthology
44, 153–168.
Sapp, K.K. and Loker, E.S. (2000a) Mechanisms underlying digenean-snail
specificity: role of miracidial attachment and host plasma factors.Journal of
Parasitology86, 1012–1019.
Sapp, K.K. and Loker, E.S. (2000b) A comparative study of mechanisms under-
lying digenean-snail specificity:in vitrointeractions between hemocytes and
digenean larvae.Journal of Parasitology86, 1020–1029.
Sapp, K.K., Meyer, K.A. and Loker, E.S. (1998) Intramolluscan development of
the digeneanEchinostoma paraensei: rapid production of a unique mother
redia that adversely affects development of conspecific parasites.Invertebrate
Biology117, 20–28.
Sewell, S. (1922) Cercariae indicae.Indian Journal of Medical Research10, 1–327.
Smith, N.F. (1999) Life history dynamics of the mangrove snail,Cerithidea
scalariformis, and the recruitment patterns of its trematode parasites. PhD
thesis, University of California, Santa Barbara.
Smithers, R.S., McLaren, D.J. and Ramalho-Pinto, F.J. (1977) Immunity to schisto-
somes: the target.American Journal of Tropical Medicine and Hygiene26(S),
11–19.168 K.D. Lafferty