1 JUNE 1999
A. Miquelis, C. Rougier, R. Pourriot-1998
Hydrobiologia, 386 : 203-211 (from Current Contents)
Abstract:
The impact of turbulence and turbidity on Brachionus calyciflorus grazing rate was determined in short feeding periods (10 min), using labelled Chlorella pyrenoidosa. The response to water motion of B. calyciflorus depends on its physiological state: the grazing rate of recently fed amictic females stomach green (with one or two eggs) is significantly reduced in agitated environments compared with non-agitated environments. In contrast, the grazing rate of starved amictic females is not reduced by water motion, whatever its velocity (V-1=0.18 m/s and V-2=0.22 m/s). In the presence of suspended particles (3-6-mu m silica beads), a larger reduction in grazing rate is observed in agitated water at any water velocity (V-1=0.18 m/s or V-2=0.22 m/s), than in stagnant water. A synergy between turbulence and turbidity is unfavourable to feeding of rotifers.
(Univ Provence, UPRES 2202, 1-3 Pl Victor Hugo, Case 31, F-13331 Marseille, France, e-mail: miquelis@hotmail.com)