Selenium (Se) is an essential trace element that has vital effects on growth, antioxidant capacity and early
development in marine fish larvae. However, traditional livefoods such as rotifer and artemia lack of Se. In this
regard, a 50-day feeding experiment was conducted in order to examine the effects of Rotifer and Artemia
enrichment with selenium nanoparticles (SeNPs) on growth, antioxidant capacity and fatty acid profile of
Arabian yellowfin seabream (Acanthopagrus arabicus) larvae. Four levels of SeNPs were used to prepare the
experimental emulsions,including control (0), 0.5, 1.0 and 5 mg SeNPs L 1. Larvae were stocked at density of 50
larvae L 1 into twelve 250-L cylindrical tanks. Tanks supplied with seawater (23 ± 1 ºC; 40.0 ± 1.0 g L 1). Green
water was used from day first until 20 days after hatch (DAH). Rotifers (15 ml 1) were offered to larvae from day
2–21 DAH and Artemia metanauplii (1–3 Artemia ml 1) were offered to larvae from day 18–45 DAH. Fish were
sampled at 0, 7, 10, 15, 22, 30, 40, 45, 50 DAH. The Se concentration in the livefoods and larval whole body
linearly increased with the increment of SeNPs level in the experimental emulsions. Larvae wet weight showed
quadratic response and increased with SeNPs up to 1 mg mg SeNPs/L, then decreased in SeNPs (5.0) group. The
activity of antioxidant enzymes including catalase, superoxide dismutase glutathione peroxidase, and total
antioxidant capacity increased but malondialdehyde level decreased in larvae fed the SeNPs-enriched livefoods
and showed both linear and quadratic responses. Lysozyme activity in the whole body of larvae fed SeNPsenriched
livefoods had both linear and quadratic responses and in the most of the sampling times was higher
than the control group. Docosahexaenoic acid (DHA) level in the livefoods and larval whole body increased with
SeNPs. In conclusion, livefoods enrichment with SeNPs at 1 mg L 1 is recommended to elevate the antioxidant
capacity and non-specific immun
