Oxygen consumption of Mugil cephalus on several temperatures under brackish water conditions

Abstract

Abstract Two experimental groups were applied to measure oxygen consumption (OC) of young grey mullets Mugil cephalus (TL: 27.3±2.1 cm; TW: 187.9±45.8 g) at different temperatures (15, 20, and 25°C). Specimens of fish from seawater (30 psu) and freshwater (0 psu) were transferred in to brackish water (15 psu). Rate of fish OC after rearing in brackish water, showed significant difference (P<0.05) in that the grey mullets consumed 90.9, 116.8, and 172.1 mg O2/kg/h at temperatures of 15, 20, and 25°C, respectively. In fish from freshwater transferred to brackish water, grey mullets consumed 80.5, 114.4, and 161.5 mg O2/kg/h at 15, 20, and 25°C, respectively (P<0.05). The results showed that the highest oxygen consumption was found at 25°C compared to those at 15 and 20°C. However, the OC from both groups did not differ significantly (P>0.05). It can be concluded, that the OC rate of grey mullets on brackish water has the tendency to increase by temperature rise.