Population ecology of Anomalocardia brasiliana (Gmelin, 1791) (Bivalvia, Veneridae) on Paranaguá bay, Paraná, Brazil

Abstract

From April 1996 to December 1997, the spatial and temporal distribution and some aspects of the population structure of the pointed venus, Anomalocardia brasiliana (Gmelin, 1791), was studied on two tidal flats of the Paranaguá Bay (PR, Brazil). A. brasiliana was observed from the entrance of the estuary, with mean salinity higher than 30, to the inner sectors with a minimum salinity 17. Larval settlement was observed to occur preferentially on the higher level of the tidal flats, where population densities were significantly lower. Summer reductions in population density were probably due to an increase in predation and pluviosity during this period, and to intrinsic population factors, that may favor the settlement of A. brasiliana during autumn.