Nutritional Performance of Juvenile Red Drum (Sciaenops ocellatus) Fed Various Fish, Shrimp, and Squid Diets

Abstract

Aquaculture is the fastest-growing sector of protein production in the world. Due to the rising costs of fishmeal used as a critical ingredient to make pelleted fish feed, the industry is moving to replace fishmeal as a primary protein source without reducing the growth rate of aquacultured fish. A 12-week feeding trial utilizing juvenile red drum (Sciaenops ocellatus) was conducted to determine the performance of various combinations of natural diet components including fish (Decapterus punctatus), shrimp (Litopenaeus vannamei), and squid (Loligo opalescens and Illex), in addition to a commercial fishmeal-based pelleted feed, fed isocalorically to identify if there is an optimal combination for red drum growth and health. These results can provide information to develop fishmeal replacement diets (FMRDs) that can more closely mimic the performance of natural diets. Traditional aquaculture metrics showed that fish fed the diet comprised only of fish had the highest specific growth rate, condition factor, and protein conversion efficiency, with the lowest feed conversion ratio, indicating the fish component was the highest performing component for red drum growth on a calorically fixed ration. There were significant differences among eight groups found for traditional aquaculture metrics ( $p<0.05$ ). The commercial pelleted feed performed better than all but the fish only natural diet treatments in terms of growth on a fixed ration, which indicated that it is nutritionally balanced. The results of this study show that there were performance differences between juvenile red drum fed various natural diets. There has been an investigation into the metabolome of these fish to identify potential metabolites for supplementation into FMRDs, which is not addressed in this paper.