Altered Feeding Electivity of the Bluegill From Increased Prey Accessibility Following Macrophyte Removal
Year: 1979
Type: article
Abstract: Species diversity and biomass of invertebrates in stomachs of young-of-the-year, 1- and 2-year-old bluegill (Lepomis macrochirus) were examined in relation to variation in the benthos of a pond treated with a herbicide. Vascular plant biomass, mainly Potamogeton spp, were nearly eliminated by the treatment; at the 0-1 m depth stratum, the biomass dropped from 481.2 g dry weight per m2 to 0.3 g dry weight per m2. Density of the phytomacrofauna declined but the abundance of detritivorous invertebrates increased in post-treatment collections. Averages of total numbers and biomass of zooplanktonic and benthic organisms in stomachs were larger in the sampling period following treatment. Species diversity ( d) of macroinvertebrates in the fish stomachs increased following the herbicide application even though the diversity of macroinvertebrates in the environment declined. Species diversity of the total food ration, including the zooplankton, diminished following treatment because of predator electivity for only the cladoceran species in the zooplankton. The authors suggest that both prey density and vulnerability are of importance in predator selection and that a preferred species, if vulnerable, may be selected even when not relatively abundant.
Author: Maureen Diggins
Language: English
Subfield: Ecology
Field: Environmental Science
Domain: Physical Sciences
SDG: Life on land
Open Access status: diamond
OpenAlex ID: W2167050719