Synoptic measurements of ingestion rate, ingestion selectivity, and absorption efficiency of natural foods in the deposit-feeding molluscs Nucula annulata (Bivalvia) and Hydrobia totteni (Gastropoda)

Abstract

Three of the most important aspects of deposit-feeding behaviour are ingestion rate, ingestion selectivity and absorption efficiency of ingested food. The purpose of the experimental results described here is to allow estimation of these traits for animals offered natural sediments. Experiments were performed to measure ingestion rate and selectivity of inorganic, organic and microbial fractions, and absorption efficiency of ingested microbes by Nucula annulata (Bivalvia) and Hydrobia totteni (Gastropoda) offered silt-clay sediments. N. annulata selectively ingested the organicand bacteria-rich sediment fraction, and absorbed bactena with 72 % efficiency. H. totteni ingested the sediment non-selectively, and absorbed sediment-associated bacteria and algae with approximately 40 % efficiency.