Effects of α-tocopherol supplementation of rotifers on the growth of striped trumpeter Latris lineata larvae

The effect of dietary α-tocopherol (α-T; vitamin E) on the performance of striped trumpeter larvae was assessed using a dose–response design. Five tuna oil/lecithin/water emulsions containing between 0% and 4% (40 mg g −1) dry weight (DW) of α-T were fed to rotifers, resulting in rotifer α-T concentrations between 114 and 1040 μg g −1 DW. These rotifers or a reference diet of rotifers enriched with AlgaMac 2000 (AM) were fed to larvae from first feeding at 5 days post-hatch (dph) until 23 dph. In larvae fed the emulsion-enriched rotifers, tissue concentrations of α-T were correlated to dietary concentrations. Larvae at 5 dph contained 276 μg α-T g −1; concentrations in most larvae had reduced at 23 dph (to between 121 and 225 μg α-T g −1) except for those fed highest α-T, which contained 356 μg g −1. Larval weight at 20 dph, and length at 14 and 23 dph were positively correlated with dietary α-T concentration. Interpolation of data from the regression curves showed that higher dietary α-T (i.e. ≥437 μg α-T g −1) gave a maximum 7% increase in larval length and a maximum of 10% increase in weight. Larval survival was extremely variable (average 37.0±30.1%). Though not statistically significant, average survival was apparently higher (48.4±28.2%) in larvae fed diets containing ≥437 μg α-T g −1 than those fed diet with lower α-T, i.e. ≤144 μg α-T g −1 (25.6±30.3%), with larvae fed 221 μg α-T g −1 having intermediate survival (37.2±32.3).