The energetics of Corophium volutator (Pallas)

Abstract

An energy budget has been constructed for the mud-dwelling amphipod Corophium volutator. Population production was estimated from field samples while metabolism was calculated by applying the results of laboratory measurements to a model of the population. The measurement of ingestion rates and assimilation efficiency proved difficult and indirect methods were found to be necessary in order to calculate energy intake. Observations and experiments on the feeding biology of Corophium are described and the possible effect of the population on algal productivity in the salt marsh is discussed. Some of the difficulties involved in the study of invertebrate feeding energetics are pointed out. Of the total estimated energy intake, less than 30% was absorbed and assimilated. Gross growth efficiency was in the order of 10% but production was high in relation to assimilation - 40% of assimilated energy went into production and the ratio of production to mean biomass was also high. The potential importance of corophium as a component of salt marsh energy flow is discussed.