Credit: Ismael Radwan (Egypt)
The photo shows the facilities what are in use during the hormonal treatment of Nile tilapia, Oreochromis niloticus. One may notice that the relatively small size of tanks which enables the matching with the possible number of treated tilapia fry keeping in mind that the fecundity of Nile tilapia (no. eggs/female) is most likely in hundreds and/or reaching/exceeding the thousand. Therefore, the tanks used during the treatment consider the number of treated fry by batch. In this particular facility, the under-ground water is the only water source and so, the trickling devices above the tanks in an attempt to aerate the water especially the underground water is lacking oxygen.