EFFECTS OF BELL DIAMETERS AND PREY CONCENTRATIONS ON INDIVIDUAL FEEDING RATES OF JELLYFISH AURELIA sp.1
水母伞径和饵料密度对海月水母(Aurelia sp.1)捕食率的影响

The blooms of Aurelia aurita population greatly damage the health of marine ecosystem and the sustainability of fish resources utilization.To determine the effects of bell diameters and prey concentrations on the individual feeding rates of Aurelia sp.1,feeding rates of Aurelia sp.1 on Artemia nauplius were studied in laboratory.Bell diameters significantly affected the individual feeding rates of Aurelia sp.1(P<0.01).When medusa bell diameters were in the range of 1 to 8cm,the relationship between bell diameters and individual feeding rates was y = 0.044x + 0.125(R2 = 0.9036).A significantly linear relationship was also found between the prey concentrations and individual feeding rates of the medusae(P<0.05).In the range of prey concentration,0.25—26.11mgC/L,individual ingestion rates of Aurelia sp.1 increased with the increase of the prey densities.The relationship was y = 0.508x(R2 = 0.958).The medusae still fed actively,with even superfluous feeding at high prey concentration.The diel continuous feeding experiments indicated that there was no significant diurnal feeding rhythm in Aurelia sp.1 when food resource was sufficient.The findings provided quantitative parameters to evaluate the grazing impacts of Aurelia sp.1 on zooplankton communities.Also superfluous feeding indicated that the grazing impacts predicted by biomass and metabolism of jellyfish was underestimated.