Selective Feeding and Epipsammic Browsing by the Deposit-Feeding Amphipod Corophium volutator

Abstract

Feeding behavior of the amphipod Corophium volutator (Pallas), related to particle size was studied by comparing carbon content in ingested food and faeces with carbon content in the food offered. Assimilation efficiency is independent of particle size. In addition to swallowing particles, C. volutator browses upon particles (epipsammic browsing) of both smaller and larger size than the maximum that can be swallowed. Epipsammic browsing is responsible for about 90 % of total carbon ingestion under the experimental conditions. Scanning electron microscopy of gnathopods reveals structures accounting for this feeding mechanism. Epipsammic browsing was not previously described for C. volutator, which may be a highly selective deposit feeder.