The effects of Cystoseira indica extract on the level of oxidative stress and survival rate of common carp, Cyprinus carpio

Due to the effects of seaweeds on defense mechanism of antioxidant enzymes and improving the oxidant/antioxidant status, extracts of Cystoseira indica on some oxidative stress index of common carp (Cyprinus carpio) gill tissue by adding to the rearing water environment during three weeks culture was evaluated. The extract was added in three different levels of 1%, 5% and 10% Cystoseira indica algae per liter of rearing water. Storage of fish were stocked at a density of 5 fish in each 10-liter of aquarium. The experiments were set up in three treatments containing Cystoseira indica extract and a control group (each with three replicates). Sampling of fish was conducted to measure oxidative stress index on days 7, 14 and 21. According to the results, the highest survival rate, specific growth rate and the lowest feed conversion ratio were observed in 10% of algae extract. Superoxide dismutase and catalase activity in the treatment of 10% algae extract compared to control treatment significantly increased and activity levels of malondialdehyde was significantly reduced. The level of glutathione peroxidase activity in different treatments Seaweed was no significant difference with control treatment. The results of the present study showed that adding 10% of algae extract to the rearing medium of common carp improves the growth indices as well as enhances antioxidant defense system by increasing the of antioxidant enzymes activity.