Effects of Feeding Frequency on Growth, Body Composition and Size Variation of Black Seabream, Acanthopagrus schlegelii

Abstract

To evaluate the effects of different feeding frequencies on growth performance, size variability and body composition of juvenile black seabream, Acanthopagrus schlegelii, a 35-day experiment was carried out in a semi-closed recirculating system. The experiment set up consists of three treatments in triplicates of nine rectangular tanks (50 cm L x 37 cm W x 24 cm H), a sump, oxygen circulators, a water pump for each treatment. Water temperature was controlled using an electric heater with temperature controller installed for the whole system. Feeding frequencies were set at one, two and three times/day (T1, T2, and T3) respectively. Experimental fish individual weight of 6.3±0.40 g and total length of 5.95±0.25 cm were stocked in each tank. Water temperature, pH, dissolved oxygen (DO) and salinity were maintained at 25.5±1.5° C, 7.5±0.5, 9.0±1.0 mg/L and 34±1.0 ppt respectively. At the end of the experiment, T3 displayed a significantly better growth (P < 0.1) in weight, total length and specific growth rate (SGR) than T1 but not with T2. Food conversion (FC), survival rates (SR) and condition factor (K) were not significantly different (P > 0.1) among the treatments although they were improved with increasing feeding frequency. For size variability and dispersion, uniformity indexes, coefficient of variation (CV), skewness and kurtoses for body weight, length and K were determined. CV for body weight and length decreased with increasing feeding frequency with significant differences (P < 0.1), while CV for K was fairly uniform but there were no significant differences (P > 0.1) among all the treatments. Skewness for body weight and K for T3 were significantly different from T1, and T2 (P > 0.1). Kurtoses for body weight and K significantly decreased with increasing feeding frequency (P > 0.1) observed among treatments. In this study, the results indicate that, feeding juvenile black seabream three times a day improves their performance in terms of growth, condition factor, survival rates and uniformity than feeding once or twice a day.