Between June 1982 and February 1983 a survey of the marine molluscs of the Channel of São Sebastião, State of São Paulo, was carried out A total of 195 species were found: 103 gastropods, 87 bivalves, 4 chitons, and 1 scaphopod. 140 species belong to the Caribbean fauna, 22 are circumtropical or worldwide in distribution, 13 are endemic to the Brazilian coast, and 10 belong to the Patagonian fauna. Most species (77,6 %) were found in the intertidal zone. 142 species, recorded for the region by other authors and not found in the present survey, are also listed. A reduction in the number of species was also observed comparing the present data (1982-1983) with more recent data from other authors (1987-1989). This situation is probably due to chronic pollution and other environmental impacts.
Marine molluscs; Community composition; Intertidal environment; Check lists; Biological survey; Environmental impact; Gastropoda; Bivalvia; Polyplacophora; Scaphopoda; São Sebastião; São Paulo; Brazil