Abstract

S. Watcharapong and N. Jennarong

A 120 dayfeeding trial was conducted to evaluate the reproductive performance, egg and larval quality and egg fatty acid composition in Spotted Babylon (Babylonia areolata) broodstock fed with natural food (fresh meat of carangid fish, Seleroides leptolepis,) and one of four experimental formulated diets containing 5 or 15% of dietary lipid from either tuna oil or a mixture of tuna oil and soybean oil (6:4) labeled as 5% TO, 15% TO, 5% MO and 15% MO respectively. Using trash fish as a control food resulted is the lowest levels of in 20:5 n -3, 22:6 n -3 and 20:4 n -6 fatty acids compared to those of all experimental diets, while the highest contents of those fatty acids were found in the 5% TO diet. Statistically significant differences in reproductive performance between dietary treatments with the best reproductive performance were found only for females fed the 5% TO diets, but egg and larval quality showed no variability among females fed trash fish and all experimental diets. No significant differences were observed in the survival duration in the starvation tolerance test for females fed trash fish or any of the experimental diets. However, the fatty acid profile of egg capsules was significantly affected by the dietary treatments. The levels of major fatty acids (20:5 n -3, 22:6 n -3 and 20:4 n -6) in egg capsules produced from females fed diets containing 5% tuna oil (5% TO) was significantly higher than those from females fed trash fish or other experimental diets. We therefore conclude that formulated diets resulted in successful reproduction and high essential fatty acids in egg capsules comparable to the use of trash fish.