Production of Florida pompano, Trachinotus carolinus, has been shown to be commercially feasible based on joint FAU-HBOI and USDA-ARS research projects. Many of those projects focused on nutrition. Probiotics and prebiotics have been shown to result in enhanced health and production of aquatic species compared to probiotics alone. A previous reported study comparing various levels of prebiotics added to larval pompano diets showed no increase in production from 5 to 50 g but did show changes in health indices. The present study was conducted to determine whether an early application of the symbiotic combination that showed promise previously would enhance the production or health of Florida pompano to market size.
The two dietary treatments used consisted of a non-synbiotic basal diet and a synbiotic diet (β-glucan + Pedicoccus acidilactici). The experiment was divided into two phases (Figure 1). Pompano (n=~12,500/tank, 2 replicate tanks/treatment) reared to larval stage received rotifers enriched with Algamac-3050 or Algamac-3050 + the synbiont combination. Following weaning, larvae were transferred to one of 8 tanks in two separate RAS systems (east system 830 L tanks and west system 1260 L tanks) and fed the same dietary treatment in pelleted form (45% crude protein, 12% lipid). In the symbiont treatment β-glucan was substituted for cellulose at 1.0 g/kg-1, and a dried P. acidilactici fermentation product (10^6) was applied in the top-coat oil. At ~50 g the two treatments were subdivided into two additional treatments, creating four new treatment groups (n= 175 fish per m3; 4 replicate tanks/treatment in the two systems [n=145/tank east and n=220/tank west]). At ~100 g fish (total n=400/replicate tank, 3 replicates/treatment; 15 fish from each phase 1 treatment were uniquely tagged in each replicate tank) were transferred into a new RAS system and grown to market size (target size ~680 g).
Production data assessed at the end of each phase included weight gain, specific growth rate and survival. Additional analysis conducted included proximate analysis (whole fish), enzyme analysis (intestinal tissue), and hematological (blood counts, lysozyme) and immune function assays (phagocytic activity, SOD activity). Production and health parameter evaluations for each experimental phase are currently underway and will be reported at AA2023.