Functional response to Daphnia carinata King when feeding on the filamentous diatom Melosira granulata

Abstract

The functional response of D. carinata feeding on M. granulata was determined from laboratory trials conducted at 20-22ºC, using a range of food concentrations (F) from 0.14 to 33.8µg (dry weight) mL^-1. The functional response could be described by an lvlev model: I (ingestion rate, ng µg^-1 h^-1) = 200 - 205 × exp (- 0.036 × F). The ingestion rate at the highest food concentration (33.8 µg mL^-1) was 140 ng µg^-1 h^-1, and there was no evidence to suggest that M. granulata either interfered with feeding at high densities or was a difficult food item for D. carinata to handle.