Performance and skeletal abnormality of striped trumpeter Latris lineata larvae and post larvae fed vitamin A enriched Artemia

Several nutritional studies have found that excess or reduced dietary vitamin A (VA) causes skeletal malformations in marine fish larvae. Feeding VA enriched rotifers to striped trumpeter (Latris lineata) from 6 to 18 days post hatch (dph) has been shown to affect vertebral column malformations but not jawmalformation. Our study examined the effect of dietary VA during the later Artemia feeding period on the prevalence of malformations. Larvae were initially reared in a 3000 l tank and fed a diet of Algamac-3050 enriched rotifers from 2 to 16 dph. At 16 dph, larvae were transferred to 24 × 300 l tanks and fed Artemia enriched with one of six doses of retinyl palmitate (VA) four times per day from 19 to 44 dph. Enrichment with emulsions containing 0 (control), 795, 1558, 3174, 4911 and 10,518 ng retinyl palmitate mg−1 emulsion resulted in an average VA in Artemia of 0, 6, 7, 27, 30 and 55 ng retinyl palmitate mg−1 dry weight (DW). The retinoid content of L. lineata at 44 dph was positively correlated with the enriched Artemia they fed on. Growth in length (15.91 ± 0.31 mm, mean ± SD) and dry weight (5.08 ± 0.32 mg), and survival (26.1 ± 2.9%), were not significantly affected at 44 dph by increasing dietary doses of retinyl palmitate. Retinyl palmitate enrichment in Artemia did not affect jaw malformation in L. lineata, which is contrary to other studies on a range of marine fish species treated with increased doses of dietary VA. By the end of the study, 54 ± 10% and 18 ± 6% of the post larvae across treatments had short lower and open jaws, respectively. Severe jaw malformations affected 50 ± 11% of the post larvae. Early culture of larvae in a larger tank was likely to reduce overall prevalence of jaw malformations compared to previous studies as interaction with tank walls was reduced. The prevalence of vertebral column malformations in 44 dph post larvae (58 ± 4%) were also not affected by dietary VA. The study suggests that the window of influence for dietary VA is during earlier development of bone structures in L. lineata