Meeting Abstract

48.3  Jan. 6  Antioxidant defenses and stress biomarkers in molluscs from Lau and North Fiji Basin hydrothermal vents OSTERBERG, J.S.*; ROMANO, J.; MCCLELLAN-GREEN, P.; Duke University Marine Lab; Duke University Marine Lab; North Carolina State University, CMAST jso6@duke.edu

Deep-sea hydrothermal vent environments are known to have extremely elevated heavy metal concentrations, especially those in the Lau Basin. How endemic organisms deal with this burden is not fully understood. Cellular mechanisms to defend against metal-induced oxidative stress include the oxyradical scavenging and metal transport tripeptide glutathione and the enzymes catalase and superoxide dismutase. Lipid peroxidation is used as a biomarker of oxidative stress. Activities of these two enzymes and levels of glutathione and lipid peroxidation were quantified spectrophotometrically in foot and endosymbiont-bearing gill tissue in gastropods of the genus Alviniconcha and mussels of the genus Bathymodiolus collected from deep-sea hydrothermal vents in the Lau and North Fiji Basins. Glutathione levels in the gastropod gills were consistently and significantly higher in the foot and similar for each site, and conversely glutathione levels in the mussel were similar in the two tissues but varied significantly among the sites. Catalase activity did not generally vary among sites in either mollusc but differed significantly between tissues in the mussel. Levels of cytosolic and mitochondrial superoxide dismutase were similar among sites and tissues but were significantly elevated in the foot tissues of both species at the White Lady vent site. Lipid peroxidation was strikingly and significantly elevated in the gills of both species at the White Lady vent site, but reduced in foot tissues at this site. These results suggest that different antioxidant defense mechanisms are prominent at different sites and in different tissues for these two molluscs and that the White Lady site is a stressful environment.