Effect of Diets and Water Temperatures on Growth Performance of Splittail Larvae

Abstract

A 4-week growth trial using a 4 × 3 × 2 factorial design (consisting of four diets, three water temperatures, and two replications of 150 larvae each) was conducted with splittail Pogonichthys macrolepidotus larvae (16 d posthatch, weighing 3.1 ± 0.5 mg [mean ± SE] and measuring 8.9 ± 0.2 mm) in three recirculation systems. The four diets were three commercial feeds (Silver Cup [SC], BioDiet [BD], and Biokyowa [BK]) and a laboratory purified-casein (PC) diet. The three water temperatures were 18, 22, and 26°C. Results indicated that the specific growth rate, total body length, condition factor, and whole body moisture of the fish were significantly (P < 0.05) affected by the diets and water temperatures, whereas mortality was only affected by the diets. The interaction of diet and water temperature was significant for the specific growth rate, total body length, whole body moisture, and mortality but not for the condition factor. Larvae fed the BK and PC diets had a higher specific growth rate and lower mortality than those fed the SC and BD diets at all temperatures. Larvae raised at 26°C grew faster and were thus significantly longer and heavier than those raised at 18°C. These results suggest that the BK or laboratory PC diet and a water temperature of 26°C were better than the other commercial feeds and water temperatures for splittail larvae under our laboratory conditions.