Nanotechnology involves the application of materials at the nanoscale to new products or processes. It is a rapidly growing industry which is currently worth one trillion U.S. dollars of global economy value by 2015, with a significant proportion on the theme of sustainability, including food production and agriculture. There are opportunities for the fisheries and aquaculture industries to use existing nanotechnologies, and to develop new applications specific to this industry. Several applications of nanotechnology for aquaculture production are currently being developed. Recently, researchers had reported that young carp and sturgeon exhibited a faster rate of growth (30% and 24% respectively) when they were fed nanoparticles of different nano-Selenium sources (nano-Se) supplemented in basal diet. This is because nano-Se was found improving the final weight, relative gain rate, anti-oxidant status as well as Glutathione Peroxidase(GSH-Px) activities and muscle Se concentration of the young carp. Moreover, nano-Se appeared to be more effective than organic selenomethionine in increasing muscle selenium content. Similarly, the growth and performance of the experimented fishes have been assessed higher at nano- level delivery of these nutraceuticals. Selenium (Se) is an essential trace element for human and animal health. It was found to be an integral part of the glutathione peroxidase enzyme, and glutathione peroxide takes part in the cellular defence against oxidative damage of cytoplasmic structures by catalyzing the reduction of hydrogen peroxide and lipid peroxides. Other literature have reported that selenomethionine is a predominant chemical form of organic selenium in feedstuffs due to their excellent bioavailability and has been reported to have higher bioavailability for Atlantic salmon and channel catfish.
Through this project, the effects of different concentrations of Selenium nanoparticle (Nano-Se) on growth performance were studied, which were incorporated as feed additives into current commercial diets for Pacific White Leg Shrimp (Litopenaeus vannamei). Young L. vannamei were divided between duplicate 2 tanks with 20 individuals per tank, for each treatment and control group. The control group were fed only normal commercial diets without Se supplement, while treatment groups were fed supplemented diets of 0.3 and 0.5 mg Nano-selenium (Nano-Se) per kg of the same commercial feed. Animals were all fed to satiation at 5% of body weight twice daily. Each tank was sampled for live shrimps regularly, and data on Weights and Lengths of all collected shrimps were recorded at several time points, including the initial and the end of experiment, which were treated as initial weight and final weight, respectively. At the same time, shrimp survival was recorded based on individual counts in each tank. After 7 weeks of feed supplementation, statistical analysis was also carried out on the data collected.
Results from experiments showed that there were no significant differences in the lengths and weights of the L. vannamei shrimps between treatment groups after 7 weeks, although shrimps which were fed 0.5mg Nano-Se per kg feed were comparatively heavier than those fed the control diet. Shrimps from all treatment groups showed healthy growth over the 7 weeks of experiments, and no mortality was observed from consumption of the feed, suggesting that supplementation with Nano-Se at these concentrations was non-toxic to the shrimp. Future directions include screening and grading of shrimps for more even initial size and weights, increasing water temperature during culture, and testing the effects of higher Nano-Se supplement concentrations in commercial feed.