Within the group of elasmobranchs, SOD activity was significantly lower in I. oxyrinchus than in P. glauca (p = 0.01) (Fig. 1-IA); while among teleosts the activity of SOD was lower in T. macdonaldi than in C. hippurus (p = 0.003) and K. audax (p = 0.002) (Fig. 1-IB).