Abstract

1. Carbon budget parameters were measured for young-of-the-year Monoporeia affinis in a combined field and laboratory (microcosm) study, designed to quantify the role of sediment bacteria as a carbon source for juvenile amphipods. Special emphasis was placed on the stimulative effects of amphipod activity (foraging, feeding, bioturbation) on sediment bacterial production and abundance by including the carbon thus generated in carbon budget calculations.2. Amphipod production was clearly higher at lower densities, suggesting strong intraspecific interactions. Negative production was recorded at amphipod densities of 10000 and 20000 ind. m-2. Negative production was not accompanied by a decrease in amphipod total lipid content, however, probably due to the lack of easily mobilized lipids in juvenile amphipods. Amphipod respiration rate was 0.45 mug O2 ind.-1 h-1, or 0.15 mug C ind.-1 h-1. Sediment bacterial carbon content averaged 1.31 and 0.90 mg g-1 DW under field and laboratory conditions, respectively.3. Bacterial carbon was not quantitatively important for Monoporeia. Due to higher bacterial abundance and production in natural, stratified sediment, assimilation of bacterial carbon was highest for the field population, providing 6.3% of the amphipods' carbon requirement. In microcosm populations, bacterial carbon accounted for between 1.7 and 5.2% of overall amphipod carbon demand, increasing with amphipod density and bioturbation.4. Ingestion rate, rather than the quantity of bacterial carbon in the sediment, was found to limit absorption of bacterial carbon from the sediment.

Published in

Freshwater Biology
1994, Volume: 32, number: 3, pages: 553-563

SLU Authors

• Johnson, Richard

  • Department of Environmental Assessment, Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Ecology


Publication identifier

DOI: https://doi.org/10.1111/j.1365-2427.1994.tb01146.x

Permanent link to this page (URI)

https://res.slu.se/id/publ/88290