Fresh WaterSnailsBiomphalariaSchistosoma mansoniDisease VectorsLymnaeaMolluscacidesBulinusEchinostomaCercariaHost-Parasite InteractionsAnimal ShellsSchistosomiasis mansoniEgyptMartiniqueGuadeloupeSchistosomaTrematodaSaint LuciaPopulation DensityHemolymphHemocytesInvertebrate HormonesBrazilSchistosomiasisHelix (Snails)EuphorbiaNiclosamideSilver StainingLatexOocystsCompetitive BehaviorBiological PhenomenaConus SnailLethal Dose 50TilapiaEchinostomiasisLakesAngiostrongylusDNA, HelminthPhylogenyPest Control, BiologicalArgentinaGillsPalaemonidaePiperaceaeParasite Egg CountEcologyPest ControlDalbergiaMolecular Sequence DataRiversDNA, Ribosomal SpacerSeawaterFishesSpecies SpecificitySchistosomicidesKiller Cells, NaturalEcosystemFreshwater BiologyRandom Amplified Polymorphic DNA TechniqueCubaPlant ExtractsLarvaWater MicrobiologyDNA, RibosomalPredatory BehaviorSchistosoma haematobiumEnvironmentGenetic VariationPlanktonPolymerase Chain ReactionPolymorphism, Restriction Fragment LengthTrematode InfectionsSeasons