FUNCTIONAL-RESPONSE TO DAPHNIA-CARINATA KING WHEN FEEDING ON THE FILAMENTOUS DIATOM-MELOSIRA GRANULATA

The functional response of D. carinata feeding on M. granulata was det ermined from laboratory trials conducted at 20-22 degrees C, using a r ange of food concentrations (F) from 0.14 to 33.8 mu g (dry weight) mL (-1). The functional response could be described by an Ivlev model: I (ingestion rate, ng mu g(-1) h(-1))=200-205 x exp(-0.036xF). The inges tion rate at the highest food concentration (33.8 mu g mL(-1)) was 140 ng mu g(-1) h(-1) and there was no evidence to suggest that M. granul ata either interfered with feeding at high densities or was a difficul t food item for D. carinata to handle.