摘要
Present study deals with the effects of glyphosate-based herbicide,Excel Mera 71 on Anabas testudineus,Heteropnestes fossilis and Oreochromis niloticus in field conditions(1.85 kg/ha)based on anti-oxidative,metabolic and digestive responses.For this study following biomarkers viz.,acetylcholinesterase(AChE),lipid peroxidation(LPO),catalase(CAT),glutathione-S-transferase(GST),alkaline phosphatase(ALP),aspartate aminotransferase(AST),alanine aminotransferase(ALT),amylase,lipase and protease were investigated in gill,stomach,intestine,liver,kidney,brain,muscle and spinal cord of the concerned fish species.Enzyme activities were significantly altered by glyphosate exposure after 30 days,these activities were tissue as well as species specific.The results suggested that these biomarkers could be used to assess the ecological risks of glyphosate on fish.Bioaccumulation factor(BAF)studied in different aquatic natural macrophytes showed order of Alternanthera philoxeroides>Azolla pinnata>Lemna sp.(Minor)>Lemna sp.(Major)>Pistia stratiotes,while transfer factor(TF)showed the order of Pistia stratiotes>Alternanthera philoxeroides>Lemna sp.Bioconcentration factor(BCF)study showed maximum accumulation of glyphosate in liver,kidney or intestine,and minimum either in bone or stomach irrespective of fish species.An integrated biomarker response(IBR),which uses a battery of biomarkers to calculate the standardized scores for each biomarker responses ranging from physiological to biochemical/molecular responses,was evaluated by combining the multiple biomarkers into a single value to evaluate quantitatively the toxicological effects of glyphosate.In general,the multiple indices exhibited variations and A.testudineus was more affected than other fish species;maximum IBR value was observed for LPO and minimum in case of ALT.The order of integrated biomarkers caused by glyphosate treatment was recorded as follows:LPO>Amylase>CAT>AST>Protease>Lipase>ALP>GST>AChE>ALT for A.testudineus,LPO>AChE>AST>Protease>CAT>Amylase>Lipase>GST>ALP>ALT for H.fossilis and AChE>CAT>LPO>AST>Amylase>GST>Protease>ALP>Lipase>ALT for O.niloticus.Finally,IBR analysis is able to distinguish the variations between different parameters and might be a useful tool for the quantification of integrated responses induced by glyphosate toward fish.
基金
The authors like to thank the Head,Department of Environmental Science,The University of Burdwan,Burdwan,West Bengal,India for providing the laboratory facilities and library facilities during the course of research.We also like to thank the INSPIRE Program Division,Department of Science&Technology,Govt.of India(DST/INSPIRE Fellowship/2011/164,Dt.29.09.2011)for the financial assistance.We are also thankful to the respective reviewers for improving our manuscript.
