Brown tides have recurred in estuary areas globally,but trophic interactions between the causative species Aureococcus anophagefferens and planktonic copepods remain poorly understood.In this study,we investigated per...Brown tides have recurred in estuary areas globally,but trophic interactions between the causative species Aureococcus anophagefferens and planktonic copepods remain poorly understood.In this study,we investigated performance(ingestion,growth,development and reproduction) of the planktonic copepod,Pseudodiaptomus poplesia,offered either mono-algal or mixed-algal diets containing a Chinese strain of A.anophagefferens.A typical Michaelis-Menten pattern existed between ingestion rate and food level when copepod fed on the monoalgal diet of this species.Nauplii exhibited the highest maximum ingestion rate(Imax) than copepodids and adult females.In addition,Imax value was higher in nauplii feeding on A.anophagefferens than on Skeletonema costatum.When fed mixtures of A.anophagefferens and S.costatum,P.poplesia selected against A.anophagefferens cells,but less strongly at the naupliar stage.Nauplii did not undergo metamorphosis and died at late naupliar stages feeding on A.anophagefferens alone,similar to those under starvation.Furthermore,the presence of A.anophagefferens greatly reduced the reproduction rate of females in mixtures but did not influence the growth rate of copepodids.These results suggest that P.poplesia nauplii may exert grazing pressure on A.anophagefferens population during a brown tide,which,however,may not be persistent because of copepod population decline.展开更多
基金The National Natural Science Foundation of China under contract No.41276153the Joint Project of National Nature Science Foundation of China-Guangdong under contract No.U1301235+1 种基金the Public Science and Technology Research Funds Projects of Ocean under contract Nos 201305003-2 and 201305010-4the Fundamental Research Funds for the Central Universities
文摘Brown tides have recurred in estuary areas globally,but trophic interactions between the causative species Aureococcus anophagefferens and planktonic copepods remain poorly understood.In this study,we investigated performance(ingestion,growth,development and reproduction) of the planktonic copepod,Pseudodiaptomus poplesia,offered either mono-algal or mixed-algal diets containing a Chinese strain of A.anophagefferens.A typical Michaelis-Menten pattern existed between ingestion rate and food level when copepod fed on the monoalgal diet of this species.Nauplii exhibited the highest maximum ingestion rate(Imax) than copepodids and adult females.In addition,Imax value was higher in nauplii feeding on A.anophagefferens than on Skeletonema costatum.When fed mixtures of A.anophagefferens and S.costatum,P.poplesia selected against A.anophagefferens cells,but less strongly at the naupliar stage.Nauplii did not undergo metamorphosis and died at late naupliar stages feeding on A.anophagefferens alone,similar to those under starvation.Furthermore,the presence of A.anophagefferens greatly reduced the reproduction rate of females in mixtures but did not influence the growth rate of copepodids.These results suggest that P.poplesia nauplii may exert grazing pressure on A.anophagefferens population during a brown tide,which,however,may not be persistent because of copepod population decline.