title: Seston quality controls zebra mussel (Dreissena polymorpha ) energetics in turbid rivers.
abstract: Feeding processes and energetic balance of zebra mussels were both related to the quantity and quality of natural seston. Filtration rate and pseudofeces production increased while clearance rate remained constant with increasing seston concentration. Ingestion rate, assimilation efficiency, and assimilation rate all increased with increasing food quality, measured as the ratio of organic to inorganic material in the seston. Respiration rate did not change with either food quantity or quality. As a result, scope for growth declined with decreasing food quality, and fell below 0 cal mg-1h-1at an organic:inorganic ratio of 0.5. The association between feeding processes and food quality appears related to a breakdown in the ability of zebra mussels to selectively ingest high-quality organic particles when the organic content of the seston is low. Ingestion, assimilation efficiency, assimilation rate and scope for growth were all higher when seston was amended with an addition of a natural assemblage of algae. Food quality may be a better indicator of environmental conditions suitable for growth than food quantity. These results suggest that the conditions of high suspended inorganic sediment concentrations in large turbid rivers represent a difficult growth environment for the zebra mussel.
authors.affiliation: Department of Urban and Regional Planning, University of Illinois at Urbana-Champaign and Illinois Natural History Survey, 611 E. Lorado Taft Drive, Champaign, IL 61820, USA Fax:+1-217-2441717, e-mail: ddws@uiuc.edu, , , , , , US.
authors.forename: Daniel W
authors.initials: DW
authors.lastname: Schneider
authors.affiliation: Pacific Estuarine Research Laboratory, San Diego State University, 5500 Campanile Drive, San Diego, CA 92182, USA, , , , , , US.
authors.forename: Sharook P
authors.initials: SP
authors.lastname: Madon
authors.affiliation: River Research Laboratory of the Forbes Biological Station, Illinois Natural History Survey, 17500 E. CR 1950N, Havana, IL 62644, USA, , , , , , US.
authors.forename: James A
authors.initials: JA
authors.lastname: Stoeckel
authors.affiliation: River Research Laboratory of the Forbes Biological Station, Illinois Natural History Survey, 17500 E. CR 1950N, Havana, IL 62644, USA, , , , , , US.
authors.forename: Richard E
authors.initials: RE
authors.lastname: Sparks
keywords: Key words Food quality; Particle selection; Pseudofeces; Seston; Suspended sediment