Effects of small-scale turbulence on feeding rate and gross-growth efficiency of three <i>Acartia</i> species (Copepoda: Calanoida)

Abstract

Experiments designed to test the effects of small-scale turbulence on the feeding rates and gross-growth efficiency of calanoid copepods have been performed within a wide range of controlled food concentrations. Turbulence significantly enhanced feeding rates only at food concentrations lower than the ingestion saturating level. Gross-growth efficiency (the quotient carbon-egg production/carbon-food ingested) of the different Acartia species studied showed different patterns of response to turbulence, in agreement with the hydrodynamic characteristics of their habitat. Furthermore, experiments conducted on Acartia clausi at two different intensities of turbulence indicate a shift in the response, with enhancement of feeding at low intensities of turbulence and negative interference at higher intensities.