Feeding physiology of the Anomalocardia brasiliana (Gmelin, 1791) (Mollusca: Bivalvia)

Abstract

Little investigation has been carried out on the feeding physiology of filter-feeding bivalves in native species of Brazil. However, this information is essential for future studies on its cultivation, and for the interpretation of ecological characteristics of the species. Among the infaunal mollusk species, the bivalve Anomalocardia brasiliana is of great commercial interest, though little is known about its feeding rate. This work presents the results of four experiments carried out using different size classes of A. brasiliana collected at different times of the year. Based on the data for natural seston, mass of feces and pseudofeces produced and its respective organic and inorganic contents, the clearance rates, filtration, rejection, ingestion and absorption efficiency were estimated by the biodeposit method. It was observed that the A. brasiliana presents similar behavior to the majority of infaunal bivalves investigated worldwide. However, its rejection rate proved to be independent of seston variation, which leads to a low ingestion rate at seston concentrations below 10 mg.L-1. The low capacity to select the organic matter present in the seston was attributed to the high organic content present in the particulate matter in suspension in the Baía Sul of the Ilha de Santa Catarina.