Antioxidant Defense System in Cytherea Umbonella (Veneridae: Bivalves) During the Exposure of Oxidative Stress at the Intertidal Zone (Persian Gulf)

Stress reduce animal’s fitness with affecting to animal’s metabolic function, the aim of this research was to study of stress controlling function of C.Umbonella in exposure to change in grain size sediments at Kangan and Assaluyeh coastline. Five sites including 11 stations were selected. Regarding to measurement of antioxidant enzymes, Soft tissue of 192 records were extracted. Higher value of CAT enzyme reported in stations at the near stress point in site 1 (49.76 ± 1.48 U mg-1 P) and site 2 (49.64 ± 7.51 U mg-1 P). unlike to values of GR and GPx enzymes, there were no significant difference (significant value 5%) in values of CAT and SOD along to the sites and stations. proposed that CAT and SOD enzymes have better efficiency during Alarm stages but GR and GPx are more effective along the Resistant stage in exposure to stress.