A COMPARISON OF METABOLITE PROFILES OF NATURAL FEED ITEMS AND SUBSEQUENT TISSUE PROFILES IN JUVENILE RED DRUM, Sciaenops ocellatus  

Nuclear magnetic resonance (NMR)-derived metabolic profiles are emerging as a powerful tool with multiple applications in aquaculture. Here, we have examined the polar metabolite profiles of three natural feed items of many southeast United States estuarine fish. Shrimp, squid, and fish (cigar minnows) were profiled along with several tissues (liver, plasma, and muscle) of juvenile red drum over the course of a twelve-week feeding trial.

Juvenile red drum were fed an equal mixture of the three natural feed items as components of a natural (CUT) diet treatment utilized in SCDNR-NIST collaborative feed studies as a positive benchmark for performance and system validation. This natural diet has consistently outperformed experimental, pelleted feeds of various formulation. We have undertaken this study to begin to analyze the biochemical composition of the natural feed items and investigate the levels of the same compounds in fish tissue extracts by NMR to improve our understanding of red drum dietary requirements and underlying biochemical processes affected by feeds with drastically different constituents.

Plasma, liver, and muscle samples were taken initially, then again in weeks 2-5 and 9-12. Natural feed items were analyzed as individual components and composite averages were used for the whole treatment. Although fish were fed an equal amount of each of three components at each feeding, it was impossible to ensure that each fish consumed equal amounts of the three. No obvious preference or avoidance of any of the three feed components was noted. As presented previously, figures 1 and 2 show PCA plots of the final liver and muscle profiles. The CUT diet resulted in significantly different metabolite profiles than several soy-based diets (#'s 1-5).