Ictiofauna de riachos na planície costeira da bacia do rio Itanhaém, litorial sul de São Paulo

摘要: The main objective of this dissertation was to study the stream fish assemblage structure coastal plain Itanhaem river basin, in State Sao Paulo, Brazil. Fish collections were accomplished eight streams, sampled four times during year 2006, months February, May, August and November, sub-basins (of rivers Branco, Mambu, Preto sandbank streams). Itahaem basin is close large urban centers, but it still presents, several points, a well preserved surrounding vegetation, mainly areas Parque Estadual da Serra do Mar, poorly studied site. In there are two types streams: (i) clearwaters, which very oxygenated (ii) blackwaters with acidic waters. surroundings varies from stretches marginal vegetation places completely cleared for agriculture. caught an electric fishing apparatus, along 50 m stretch upriver, each time. 10% formalin and, laboratory identified (species level), measured (SL) weighed (g, total). field following traits measured: temperature (C), pH, turbidity (NTU), conductivity (μScm) dissolved oxygen (mg/l), when calculating mean three successive readings. physical channel status visually assessed. richness calculated by non-parametric estimators. Accumulation species curves drawed evaluate efficiency these estimators compare proportion accidental sub-basin. species-abundance distributions weight adjusted resource partitioning stochastic models , relationships numbers verified W statistics (ABC curves). Repeated measures analyses variance applied order richness, number individuals total among collection periods. similarity patterns analyzed non-metric multidimensional scaling PCA. Species categorized according their frequency occurence abundance weight. whole 37 collected 30 samples. estimated ricness varied between 45 species, being Jackknife 1 2 most efficient small uses data, while only presence/absence data. sub-basin Mambu streams presented higher