Effects of temperature on survival and growth of juvenile spinefoot rabbitfish (Siganus rivulatus)

Interest in culturing marbled spinefoot rabbitfish Siganus rivulatus is increasing in countries on the Eastern Mediterranean, Red Sea and Arabian Gulf. However, information on environmental tolerances and requirements for optimal growth are scarce. In the present work, the temperature requirements for spinefoot rabbitfish were investigated in two experiments. In the first experiment, juvenile rabbitfish were distributed into eight 180 L square tanks at 12 fish per tank. The temperature in four tanks was reduced at a rate of 1 degrees C day(-1) and in four tanks was increased by 1 degrees C day(-1) until the fish stopped feeding. Minimum and maximum temperatures for feeding were recorded. In the second experiment, the fish were placed in four temperature treatments (17, 22, 27, 32 degrees C) at four replicates per treatment for 8 weeks. Survival and growth were evaluated. Fish stopped feeding at 14 and 36 degrees C. Their maximum growth rate was at 27 degrees C, and survival was 100% in all treatments. The relationship between specific growth rate and temperature was parabolic, described by the equation: SGR=-0.0014 (T-3)+0.0798 (T-2)-1.3089 (T)+6.7342. The results show that S. rivulatus is a eurythermal fish whose optimal temperature for growth is circa 27 degrees C.