The role of periphyton communities in affecting the foraging behavior, assimilation, growth, and mortality of grazing snails of the genus Elimia (Prosobranchia: Pleuroceridae)

Plant-animal interaction studies in aquatic ecosystems are important because they link attributes of community trophic structure at a fundamental level. This study determined the role of periphyton communities in affecting snail grazers of the genus, Elimia. Differences in foraging behavior by E. cahawbensis when exposed to two different periphyton communities (on limestone versus sandstone substrata) were examined. Percent occurrences and movement patterns indicated that snails showed selection for periphyton on limestone. The exact cue for this preference may be related to higher algal biomass on limestone versus sandstone periphyton.;Incorporation, a component of assimilation, was conducted to verify whether the observed spatial patterns during foraging on limestone resulted in higher incorporation for that periphyton. Using ;The fate of radiolabeled dissolved organic carbon (DOC) was followed in laboratory chambers with and without snails. After 48 hours, grazing effects on organic carbon derived originally from labile amino acids were evident. E. clara assimilated 22% of the radiolabel, increased radiolabeled CO;Long term implications of selective foraging and incorporation were tested with E. cahawbensis through measurements of growth and mortality when snails were fed periphyton from limestone and sandstone in addition to treatments including heterotrophic and dead organic matter food resources. Long-term field studies were consistent with previous laboratory studies in that highest snail growth and lowest mortality occurred on limestone periphyton as a food resource.