The effects of dietary vitamin A in rotifers on the performance and skeletal abnormality of striped trumpeter Latris lineata larvae and post larvae

Several nutritional studies have linked dietary vitamin A (VA) to skeletogenesis in marine fish larvae. In our study, rotifers were enriched with eight levels of retinyl palmitate. Striped trumpeter (Latris lineata) larvae were fed rotifers twice daily, VA-enriched rotifers (morning feed) and Algamac − 3050 enriched rotifers (afternoon feed), in greenwater systems from 6 to 18 days post-hatch (dph). The VA-enriched rotifers had incorporated 0, 6, 14, 26, 57, 109, 215 and 388 ng retinyl palmitate mg− 1 dry weight (DW) following 2 h enrichment with emulsions containing 0 (control), 68, 187, 532, 1402, 2670, 4808 and 9523 ng retinyl palmitate mg− 1 emulsion. After the rotifer feeding phase (6 to 18 dph), the larvae were fed Algamac − 3050 enriched Artemia until 43 dph. The pattern of increasing VA in the enriched rotifers was not reflected in the larvae. Larvae incorporated 11.08 ± 0.27 ng total retinol mg− 1 DW (mean ± SD) when fed rotifers containing 0.93 to 2.32 ng total retinol mg− 1 DW (6 to 14 ng retinyl palmitate mg− 1 DW) and incorporated a lower level of 5.57 ± 0.30 ng total retinol mg− 1 DW when fed rotifers with 0.52 (control) or ≥ 16.31 ng total retinol mg− 1 DW (0 and ≥ 57 ng retinyl palmitate mg− 1 DW). By 43 dph, neither larval growth in length (16.0 ± 0.1 mm) or dry weight (4.57 ± 0.20 mg), nor survival (34.8 ± 10.6%), were significantly affected by increasing dietary levels of retinyl palmitate. The prevalence of vertebral column malformations in 43 dph post larvae was positively correlated with total retinol content of larvae at 16 dph (R2 = 0.55, P < 0.001). Unlike other studies on a range of marine fish species, retinyl palmitate enrichment in rotifers did not affect the type or severity of jaw malformations. By 43 dph, 81 ± 9% of post larvae displayed severe jaw malformations. Vitamin A daily inclusion of more than 123 ng total VA mg− 1 DW rotifer, equivalent to more than 35 ng total retinol mg− 1 DW rotifer (109 ng retinyl palmitate mg− 1 DW rotifers), is recommended to reduce vertebral column malformations when L. lineata larvae are reared in greenwater.