title: Factors conditioning the habitat and the density of Biomphalaria tenagophila (Orbigny, 1835) in an isolated schistosomiasis focus in Rio de Janeiro city.
abstract: The present work was carried out in a watercress garden in Alto da Boa Vista, in the city of Rio de Janeiro, Brazil. The investigation was carried out in two phases. The first one (1985-86) involved the sampling of Biomphalaria tenegophila in two areas to determine its relative populational densities. The results showed that the populations presented similar densities and dynamics. The second phase (1988-89) involved the study of the influence of some environmental factors on the establishment of B. tenagophila in watercress garden. Two factors were identified as responsible for the establishment of B. tenagophila in the garden: (1) the quality of the water entering the irrigation system, to which domestic sewage is added, and (2) alterations in the nature of the substrate, due to inadequate fertilization techniques, which employ organic matter from adjacent pigsties. Aquatic plants and hydrological parameters of the irrigation system were subsidiary factors to the establishment of B. tenagophila in the garden.
authors.affiliation: Departamento de Biologia, Instituto Oswaldo Cruz, Rio de Janeiro, Brasil.
authors.forename: D F
authors.initials: DF
authors.lastname: Baptista
authors.forename: P
authors.initials: P
authors.lastname: Jurberg
mesh_terms: D000383:Agriculture; D000818:Animals; D001700:Biomphalaria / Q000254:growth & development / Q000502:physiology*; D001938:Brazil; D004463:Ecology; D011156:Population Density; D012494:Sampling Studies; D012555:Schistosomiasis mansoni / Q000635:transmission; D014867:Water
chemical_list: D014867:Water