Abstract
The present study aimed to investigate the effects of dietary supplementation of different Zn sources on growth performance, anti-oxidative status, immune response, and ammonia stress resistance of marbled spinefoot rabbitfish, S. rivulatus. The fish were fed four experimental diets in triplicate per treatment(-1) for eight weeks. The first diet was control (without Zn supplementation), the other three treatments included supplementation with 30 mg kg(-1) zinc oxide (ZnO), Zn-Methionine (Zn-Met), and ZnO-nanoparticles (ZnO-NPs). The results revealed a significant improvement in growth performance and protein utilization with Zn-Met and ZnO-NPs supplemented treatments compared to the control and ZnO groups. There was a significant decrease in malondialdehyde content, and a significant increase in catalase, superoxide dismutase and glutathione peroxidase in all Zn supplemented groups. The lysozyme and phenoloxidase activities improved significantly with both ZnONPs and Zn-Met. Also, the electrophoretic investigation coupled with cluster analysis showed different distribution patterns of protein bands among treatments and the highest similarity was seen with ZnO and ZnO-NPs. The tolerance of S. rivulatus against an ammonia challenge was increased with Zn-Met and ZnO-NPs supplementation. In conclusion, supplementation with Zn-Met and ZnO-NPs is better than ZnO for improving growth performance, the anti-oxidative status and innate immune response of rabbitfish, S. rivulatus.