Larval performance of aquacultured Florida pompano ( Trachinotus carolinus) fed rotifers ( Brachionus plicatilis) enriched with selected commercial diets

Abstract

Selected rotifer enrichment diets were compared on the basis of growth, survival, and fatty acid content of larval Florida pompano, Trachinotus carolinus L. Two 9-day larval rearing trials were conducted using a recirculating aquaculture system. In Trial 1, two microalgae concentrates ( Isochrysis sp., ISO; and Pavlova sp.), a semi-moist paste (Protein Selco Plus, PS+), and a combination of the three diets were compared. In Trial 2, PS+ and three dry enrichment diets (Ori-Green, OG; Protein HUFA, PH; and AlgaMac 3050, AM) were compared. Larvae were fed rotifers 4 times daily at a rate of 2.5 rotifers/ml/feeding at 2–9 days post-hatch (DPH). Although larval growth in both trials was likely influenced by differences in culture density resulting from variable survival, in Trial 1 at 9 DPH standard length (SL) of larvae fed Pavlova-enriched rotifers (4.60 ±0.39 mm, mean ± SD) was greater ( P < 0.05) than that of larvae fed rotifers enriched with ISO (4.29 ±0.48 mm); and the combined treatment (4.31 ± 0.48 mm) and body depth (BD) of larvae fed Pavlova-enriched rotifers (1.21 ± 0.16 mm) was greater than that of larvae fed rotifers enriched with the combined treatment (1.08 ± 0.18 mm). In Trial 2 at 9 DPH, SL and BD of larvae fed rotifers enriched with PH (5.00 ± 0.23 and 1.24 ± 0.12 mm, respectively) was greater than that of larvae fed rotifers enriched with other diets. Survival of larvae fed rotifers enriched with PS+ was highest in both Trial 1 (24.1 ± 10.2%) and Trial 2 (34.4 ±1.6%) and was significantly greater than that of larvae fed rotifers enriched with Pavlova (7.3 ± 1.6%) and the combined treatment (6.0 ± 1.6%) in Trial 1 and larvae fed rotifers enriched with PH (21.8 ± 6.3%) and AM (14.1 ± 4.9%) in Trial 2. While lipid content and fatty acid composition of PS+ enriched rotifers closely resembled that of pompano yolk-sac larvae, n − 3 HUFA content of PS+ enriched rotifers as well as larvae fed PS+ enriched rotifers was not significantly greater than that of other diets tested in both trials.