Abstract: Treatments consisted of nine semi-purified diets containing graded levels of dietary copper （CuSO₄·5H₂O was added to a basal diet at 0, 1, 2, 3, 4, 6, 8, 10 and 12.0 mg/kg）, providing actual dietary values of 0.29, 1.31, 2.28, 3.43, 4.57, 6.61, 8.77, 10.73 and 12.89 mg/kg diet, respectively. Each diet was fed to triplicate groups of juvenile Squaliobarbus curriculus with initial body weight of 6.22 g in 300 L cylindrical fiberglass tank. The results showed that the typical dietary Cu deficient signs such as poor growth and malformation of skeleton were observed in fish fed the diets with 0.29 mg/kg diet. Fish fed the diet containing 4.57 mg/kg had the highest specific growth rate （SGR）. The lowest hepatosomatic index （HSI） and viscerosomatic index （VSI） were observed in fish fed the diet containing the highest Cu content diet （P<0.05）. Condition factor showed no significant differences among the treatments （P>0.05）. Proximate composition of fish body was significantly affected by dietary copper level （P<0.05）. Cu contents of whole body and hepatic increased with dietary Cu levels （P<0.05）. Hepatic thiobarbituric acid reactive substances （TBARS） was found to decrease with increasing dietary concentrations of copper up to 3.43 mg/kg beyond which a reverse trend in this parameter was noted. （Conclusion） Analysis by the linear regression of weight gain （WG） and feed conversion ratio （FCR） and second-order regression of whole-body Cu retention of the fish indicated that dietary Cu requirement of juvenile Squaliobarbus curriculus was 3.94~4.92 mg/kg diet.

Key words: Squaliobarbus curriculus, copper requirement, growth performance