Antioxidant responses in Mesopodopsis zeylanica at varying salinity to detect mercury influence in culture ponds

Authors : Xivanand Narayan VERLECAR, Priya Brata DAS, Karmabeer JENA

Pages : 711-718

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Publication Date : 2012-12-01

Article Type : Research Paper

Abstract :Antioxidant responses in the estuarine mysid, Mesopodopsis zeylanica, were used to assess mercury insert ignore into journalissuearticles values(Hg); metal contamination in relation to salinity. Natural mysids acclimatized at 5 psu were subjected to laboratory exposures of 5, 15, and 25 psu salinity singly and under the sublethal Hg concentration of 5 µg/L insert ignore into journalissuearticles values(one-fifth of 24 h LC50 value);. Lipid peroxidation in the test species increased with salinity variation from 5 to 15 psu and retained the same up to 25 psu with no change after Hg addition. CAT increased significantly from 5 to 15 psu before Hg influence, and GST increased after addition of the metal. However, a reduction in both these enzymes is evident at higher salinities insert ignore into journalissuearticles values(25 psu); with or without Hg. The energy cost involved in adjusting ionic concentration with hemolymph during salinity deviation from an isotonic environment could be a cause for the reduction of antioxidants and LPX accumulation at 25 psu. Insignificant changes after Hg addition, however, indicate that Hg2+ free ions did not produce much toxicity to the cellular system. The results suggest that M. zeylanica is comfortable scavenging oxyradicals within the salinity range of 5-15 psu to protect itself from anthropogenic contaminants as evidenced by elevated enzyme activity.
Keywords : Key words Mesopodopsis zeylanica mysid, , salinity, mercury, lipid peroxidation, antioxidant enzyme