The Effects of Salinity, Temperature and Feed Ratio on Growth Performance of European Sea Bass (Dicentrarchus labrax L., 1758) in the Water Obtained Through Reverse Osmosis System and a Natural River

In the present study, the effects of effluent water with varying salinity levels coming from the river and reverse osmosis device, temperature and different feeding ratios on the growth performance of European sea bass (Dicentrarchus labrax, L., 1758) fry was studied. This study was conducted in two different periods (winter and summer seasons). European sea bass fries were obtained from local hatchery with a mean weight of 5.95 (+/- 1.18) g for the first period (November 2010-January 2011) and 5.74 (+/- 1.25) g for the second period (May 2011-July 2011). Fish were progressively exposed to three experimental salinities (10-18-24 parts per thousand). These experiments were accomplished simultaneously by two repetitions and were performed between November 2010 - January 2011 (14.91 +/- 3.49 degrees C) and May - July 2011(25.23 +/- 4.82 degrees C) for 60 days in both/periods. In each experiment, 600 European sea bass fries were used. Trail fish were placed into 640 L polyester tanks, which are at three different salinity levels (10-18-24 parts per thousand) and fed by two different feeding ratios (ad libitum. and 2.5% of the body weight). As a result of the two different experiments performed in two different periods, it was found that while ad libitum feeding ratio and temperature had positive effect on the growth performance of the fish, among three different levels of the salinity, the optimum positive effect on the growth of the fish were found for the 18 parts per thousand salinity concentration.