Feeding rate and feeding frequency affect growth performance of common snook (Centropomus undecimalis) juveniles reared in the laboratory

Abstract

The effects of feeding rate and feeding frequency on the growth of laboratory-reared common snook (Centropomus undecimalis) were evaluated. Juveniles with mean±SD weight of 2.55±0.48 g and total length of 6.81±0.48 cm were divided into groups of 20 fish and reared in 30 polyethylene tanks of 50 L for 60 days. The experimental design was a 3 × 3 factorial with three feeding frequencies (F2, F4, and F6: two, four, and six daily meals, respectively), three feeding rates (R1, R2.5, and R4: 1.0, 2.5, and 4.0%/day of fish biomass, respectively), and three replicates, totaling nine treatments (F2R1, F2R2.5, F2R4; F4R1, F4R2.5, F4R4; F6R1, F6R2.5, and F6R4). The external control consisted of four meals a day offered to apparent satiety (F4S). Every 15 days, weight and length of all fish were measured to adjust the amount of feed offered. Water quality variables remained within adequate levels for this species. Feeding rate had a greater influence on performance than frequency. Survival, condition factor, and the initial and final coefficients of weight variation had no significant effect among treatments. Feeding frequency and rate directly influenced length and weight gains, feed efficiency, specific growth rate, and apparent feed conversion rate. For common snook juveniles weighing between 1 and 16 g, it is recommended to offer four to six daily meals at a feeding rate between 3.31 and 1.86% per day, which should decrease according to fish size