Formulation of the diets is shown in Table 1. Lead (II) nitrate was obtained from Sigma Chemical Co., Ltd. All diets contained 33% casein, 23% fish meal, 5% corn starch, 2% vitamin premix, and 2% mineral premix. 10% fish oil was added to meet the essential fatty acids (EFA) requirements of rock fish. Lead premix was made up of 1 g chromium with 99 g cellulose. Five isonitrogenous and isolipidic diets were formulated with supplementation of different dietary lead concentrations of 0, 30, 60, 120, and 240 mg Pb/ kg diet. All ingredients were blended thoroughly. At last, water was added into the mixture to produce stiff dough. Then the dough was pelleted by experimental feed mill, and dried for 24 h at room temperature. After processing, all the diets were packed and kept −20 °C until use.