Growth performance and hematological, biochemical, and histological characters of the Nile tilapia (Oreochromis niloticus, L.) cultivated in an aquaponic system with green onion: The first study about the aquaponic system in Sohag, Egypt

The Aquaponics system has won the interest of researchers for its multiple efficiencies in raising fish and producing crops simultaneously; however, information about the extent of this system's efficacy is scarce compared to other conventional food production methods. Hence, this study aimed to assess water quality, hematological and biochemical parameters, histological structure, and growth performances of the Nile tilapia (Oreochromis niloticus), as well as green onion (Allium cepa L.) yield. The species under study was reared in a newly developed deep-water culture (DWC), forming a prototype built in Upper Egypt, Center of Development owned by the ASRT in Sohag Governorate, Egypt. The current experiment consisted of two DWC systems. Fish were daily fed for 5days/ week with a protein content (30%), representing 2% of the total biomass. Except for water pH and temperature, the values of water quality were within the optimal ranges for tilapia culture. No significant difference was detected between the two systems with respect to the hematological, biochemical parameters, hepatic and intestinal histological structure, and growth performances, showing normal values. In addition, considering the two DWC systems, no significant difference was recorded in the growth and yield of green onion determined through fresh weight. It is deduced that aquaponics has a huge potential since it shows promising results for urban food development. At the same time, it provides new entrepreneurship and start-up opportunities. Nevertheless, more studies are recommended to overcome foreseen challenges despite its potential to be implemented in developing countries such as Egypt.