Periphyton grazing by the marine isopod Idothea chelipes was studied by exposing periphyton grown on glass slides to a gradient of grazer densities. An analysis of the algal growth rates and their relationships to grazer density revealed two groups of algae. The unicellular diatoms Licmophora ehrenbergii, Fragilaria tabulata, Navicula spp., Cocconeis costata, and the green alga Ulothrix implexa had high maximal gl’owth rates (0.90-1.47 d-l) and suffered high grazing losses (0.41-0.68 d--l per grazer ind.). The tube dwelling diatc,m Amphipleura rutilans and the cyanobacteria Lyngbya confervoides and Spirulina subsalsa had low maximal growth rates (0.38-0.81 d-l) and suffered only moderate grazing losses (0.10-0.27 d-l per grazer ind.). The species of the first group seemed to be less strongly resource limited than did the species of the second group. Grazing by I. chelipes has the potential to drive succession from the well-edible to the less edible periphyton species. Grazing on marine benthic microalgae has received much less attention than has grazing on phytoplankton. Most studies have concentrated on bulk effects on biomass, but not on selectivity, between algal species. Most selectivity studies in marine benthic herbivory have concentrated on selectivit
To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.