Objective:To study mortality of copepod Artemia franciscana against the occurrence of harmful marine algae and possible toxicological changes exhibited by binary and tertiary combinations of these harmful algae toxins...Objective:To study mortality of copepod Artemia franciscana against the occurrence of harmful marine algae and possible toxicological changes exhibited by binary and tertiary combinations of these harmful algae toxins.Methods:Tweenty four hours acute toxicity assays were performed with selected concentrations of Alexandrium minutum,Prorocentrum lima and Nitzschia N1c1 living cells.Additionally,the results were analyzed using the median-effect/combination index(CI)-isobologram equation to assess possible changes in the toxic effect induced by phytoplankton functional groups.Results:Biotoxin equivalent values obtained by immunodetection were(2.12±0.10),(8.60±1.30)and(4.32±1.67)pg/cell for saxitoxin,okadaic acid and domoic acid,respectively.The 24-h LC_(50) values estimated to saxitoxin and okadaic acid equivalents were 4.06 and 6.27μg/L,significantly below the value obtained for Nitzschia N1c1,which was established at 467.33μg/L.CI analysis applied on phytoplankton assemblages showed that both ternary mixture as the binary combinations exhibited antagonic action on toxic effects in Artemia nauplii,which were significantly lower than the toxic effect exhibited by each species studied.Conclusions:These results show that,although these harmful algae represent a serious risk to estuarine zooplankton community,the presence of phytoplankton functional groups within the same bloom can reduce the potential risk compared to the expected risk when each of the phytoplankton groups are evaluated individually.展开更多
基金Supported by Spanish Government(CTM2012-34757)the Mexican UMSNH University(CIC/11/301).
文摘Objective:To study mortality of copepod Artemia franciscana against the occurrence of harmful marine algae and possible toxicological changes exhibited by binary and tertiary combinations of these harmful algae toxins.Methods:Tweenty four hours acute toxicity assays were performed with selected concentrations of Alexandrium minutum,Prorocentrum lima and Nitzschia N1c1 living cells.Additionally,the results were analyzed using the median-effect/combination index(CI)-isobologram equation to assess possible changes in the toxic effect induced by phytoplankton functional groups.Results:Biotoxin equivalent values obtained by immunodetection were(2.12±0.10),(8.60±1.30)and(4.32±1.67)pg/cell for saxitoxin,okadaic acid and domoic acid,respectively.The 24-h LC_(50) values estimated to saxitoxin and okadaic acid equivalents were 4.06 and 6.27μg/L,significantly below the value obtained for Nitzschia N1c1,which was established at 467.33μg/L.CI analysis applied on phytoplankton assemblages showed that both ternary mixture as the binary combinations exhibited antagonic action on toxic effects in Artemia nauplii,which were significantly lower than the toxic effect exhibited by each species studied.Conclusions:These results show that,although these harmful algae represent a serious risk to estuarine zooplankton community,the presence of phytoplankton functional groups within the same bloom can reduce the potential risk compared to the expected risk when each of the phytoplankton groups are evaluated individually.
