Bivalve Feeding Selectivity

In bivalve mollusks there are two sites for the selection of particulate matter the gills/labial palps, and the stomach. Studies on selectivity by the gills have generally shown that there is a size limit below which the animal does not retain particles efficiently110). Bernard has outlined a mechanism for the selection of particulate matter which is based on the specific gravity of the particles such that the more dense material does not reach the gills and is rejected as pseudofeces111). Based on Bernard s data the particulate matter passed into the stomach would not be selected on food value. 

Provided that the particulate matter is accepted by the gills it will then undergo selection in the stomach. Selection is a function of the ciliary tracts of the various 

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Hylleberg, J. and Gallucci, V. F., Selectivity in feeding by the deposit-feeding bivalve Macoma nasuta., Mar. Biol., 32, 167, 1975. 

Quantifying the influence of physicochemical form on metal uptake from solids is an important prerequisite to developing realistic models of metal dynamics in animals. In this paper -we statistically assess the effect of selected chemical characteristics of estuarine sediments on the concentration of Zn in bivalves which ingest those sediments while feeding. Our objective is to determine what proportion of the variation in Zn concentrations of deposit-feeding bivalves from natural systems may be explained by the physicochemical partitioning of Zn in the sedimentary food of the animals. 

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