The work on survey of antioxidant defense enzymes in freshwater teleost fish and its findings enumerated in preceding pages are now summarized as follows:

1. Antioxidant enzymes (SOD, CT and GSH-Px) are responsible for scavenging the oxyanions which are produced in all the tissues wherein oxidative metabolism takes place.

2. Oxyanions or reactive oxygen species have harmful effects on all cellular components. It can react with nucleic acids, proteins, lipids and carbohydrates resulting into loss in their native configuration, if not checked by antioxidant defense systems.

3. Survey of these antioxidant enzymes which form first line of defense against oxyanions menace is conducted in fresh water teleost fishes. Six fishes taken for this study. Three of them are non-airbreathing viz. Labeo rohita, Catla catla, Hypopthalmichthys molitrix and three of airbreathing type viz. Heteropneustes fossilis, Clarias batrachus and Wallago attu..

4. Experimental fishes were collected during all the seasons winter, spring, summer and autumn.

5. The physico-chemical parameters viz. temperature, pH, dissolved oxygen content and soluble and suspended inorganic constituents of all the seasons were performed.

6. Dissolve oxygen content and temperature use are inversely proportional. During spring and summer the fish lived most stressful life (any physiological stress, UVbeta-radiation, hyperoxia, hypoxia, intoxication, heat stress and starvation, provoke ROS formation [Abele and Puntarulo, 2004]).

7. For the study of antioxidant enzymes several tissues of each fish selected. The tissues were liver, kidney, heart and gills.

8. Among all the tissues studied liver show the highest SOD and heart show the lowest. During spring season all the tissues show high value of SOD and GSH-Px and low value of CT.

9. Airbreathing fish show the higher SOD activity then non-airbreathing fish studied.

10. Temperature is directly proportional to the antioxidant activity. Higher the temperature higher antioxidant enzyme activity.