Theses and Dissertations

Date of Award


Document Type


Degree Name

Master of Science (MS)


Ocean, Coastal, and Earth Sciences

First Advisor

Dr. MD Saydur Rahman

Second Advisor

Dr. Abdullah Faiz Rahman

Third Advisor

Dr. Amit Raysoni


Increasing atmospheric temperatures influence physiological functions in aquatic organisms. In this study, I observed the effects of seasonal (field study) and laboratory heat exposure (16, 22, 26, and 30°C for 1-week) on prooxidant-antioxidant homeostasis in gills and digestive glands of American oyster. Histological analysis showed an increase in mucus secretion with elevated temperatures in both organs. Immunohistochemical analysis showed a significant increase of heat shock protein-70, dinitrophenyl, and 3-nitrotyrosine protein expressions with higher seasonal and laboratory temperatures indicating heat-induced oxidative and nitrosative stress. This was concomitant with gradual rise in cellular apoptosis. Interestingly, catalase and superoxide dismutase expressions also increased from winter to fall and 16 to 26°C in laboratory conditions, whereas decreased significantly at higher temperatures. Collectively, these results suggest that heat stress induces oxidative damage and inhibits antioxidant defense system through the overproduction of reactive oxygen species and/or reactive nitrogen species leading to increased cellular apoptosis in marine mollusks.


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