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Abstract. In the course of attempting to culture gilthead sea bream in inland brackish geothermal water, indoor and outdoor research studies have been ongoing from early 2006 at the "Bengis Centre for Desert Aquaculture" of the Institutes for Desert Research in Israel, some of which are described below. Gilthead sea bream fingerlings with an average weight of 19 g were acclimated to and reared for 56 days in brackish water of three salinities: 2.5, 3.5 and 4.5 ppt collected from three different locations. At the salinity of 3.5 ppt the fish grew best (P < 0.05) increasing their weight by 121%, while at 4.5 ppt weight increase was by 98%, and at 2.5 ppt - by 90%. In another study gilthead sea bream larvae aged 45 days post hatching, with an average weight of 0.025 g were fed yeast extract enriched Artemia nauplii plus larval dry feed and were grown in brackish water of 2.6 ppt salinity for 8 weeks reaching a weight gain of 92% at a survival rate of 83%. The control groups at sea water (39 ppt) reached at the same time a weight gain of 95% at a survival rate of 98%. In a further study gilthead sea bream juveniles with an average weight of 2.24 g were reared in brackish water with a salinity of 3.6 ppt for 8 weeks and received salt added diets of 4% and 6%. Compared with the control diet with no salt added, both salt rich diets significantly improved the fingerlings growth and survival rates as well as the feed conversion ratio. The 6% salt rich diet promoted fish weight gain by 560% which was the best performance (P < 0.05) followed by 448% weight gain with the 4% salt rich diet while the lowest performance with a weight gain of only 360% was obtained with the control (no salt added) diet. The next study with higher levels of salt added diets showed that gilthead sea bream post larvae with an average weight of 0.58 g reared in brackish geothermal water of 2.9 ppt salinity for 10 weeks grew best (P < 0.05) obtaining a weight gain of 778% with the highest survival rate of 88% when fed a diet containing 12% salt. In...