Response of Juvenile Clarias gariepinus to Varying Dietary Levels of Ionotropic Gelated Chitosan Nanoparticles Synthesized from Wasted Crab Shells

Abstract

Background: Crab shells lie wasted globally after the extraction of the edible soft tissues. Chitosan nanoparticles (CNPs) derived from these shells have the potentials to revolutionized aquaculture. Aims: Evaluated the effects of CNPs on water quality parameters, growth performance, feed utilization and survival rate of African catfish (Clarias gariepinus). Study Design:  The experimental diets were incorporated with chitosan nanoparticles at the rate of 0, 2.5 5.0 and 7.5 g kg-1 representing Treatments CNP00, CNP2.5, CNP5.0 and CNP7.5 respectively and replicated thrice. Place and Duration of Study: Department of Fisheries and Aquatic Environmental Management, University of Uyo, Uyo – Nigeria from August to November 2021. Methodology: We synthesized CNPs by ionic gelation method. Dried flour of FM, SBM, Wheat bran and yellow maize meal were analyzed for proximate composition used in the formulation of experimental diets. These were milled at 2 mm pellets, CNPs were dissolved in 0.3 liters of water and sprayed on the pellets. These were stored at 10% moisture content, in black polythene bags. Diets were fed to two hundred and sixteen fingerlings of African catfish (C. gariepinus) with mean body weight 23.86±3.11. Growth performance, feed utilization and survival rate parameters were calculated and statistically compared. Results: Ammonia was significantly (p<0.05) low in CNP7.5. The highest daily weight gain (6.98±0.81 g) was recorded in CNP7.5 while the lowest (1.02±0.01 g) was recorded in the control (CNP00). SGR, DWG, FCR, PER followed the same pattern. However, there was no difference in percentage survival rate. Conclusion: Chitosan nanoparticles supplemented at the rate of 7.5 g k-1 diet can give a better water quality, growth performance and feed utilization of C. gariepinus juvenile. Incorporation of CNPs in diet of C. gariepinus at a concentration of 7.5 g kg-1 is recommended for more profitable and sustainable culture of this fish species.