In recent decades, aquaculture has played a significant role in fulfilling the vast demand for animal protein requirements and consequently in food security. However, environmental contamination and disease prevalence are considered essential challenges for the sector. In this regard, new approaches have been paved in technology to deal effectively with such challenges. Among these, nanotechnology-as a novel and innovative tool-has a broad spectrum of uses and a tremendous potential in aquaculture and seafood preservation. It can provide new technologies for management of drugs as liberation of vaccines and therefore hold the assurance for civilized protection of farmed fish against disease-causing pathogens. This article presents a review of nanotechnology and its applications in aquaculture. Additionally, it gives a brief idea about the fish disease and classical ways of controlling pathogens. On the other hand, this review sheds the light on nanotechnology as a potential novel tool which may possibly enhance the management and the control of disease prevalence. Therefore, the importance of this technology to promote sustainable aquaculture has also been highlighted. Focusing on the role of selenium nanoparticles as an efficient element is discussed also in this article.

This study was realized to investigate the lethal dose fifty (LD50) of Streptococcus pyogenes on Nile tilapia and to determine the effect of every dose on hematological parameters as indicator of infection. In this study, a total number of 100 healthy Nile tilapia (Oreochromis niloticus) fingerlings (15 ± 0.5 g) were infected with Streptococcus pyogenes. These fish were randomly divided into five groups, each with 20 fingerlings. Five concentrations of Streptococcus pyogenes (0, 106, 107, 108, and 109 CFU/ml) were used to realize the objective of this study. Group 1 was injected inter-perennial with 0.2 ml sterilized saline solution and it was considered as a control group. The other 4 groups were injected inter-perennial at a rate of 1ml per 10 g of inoculum. All experimental groups were examined for infection signs, mortality rate and hematological parameters. The results revealed that the LD50 of Streptococcus pyogenes was 1×107 CFU/ml with ten days of tilapia infection. Also, it affected significantly on the hematological parameters and this concentration showed moderate value of infection and mortality rate compared with 1×108 CFU/ml which showed high value led to 100% immediate death of the fish. On the other hand, the concentration 1×106 CFU/ml presented normal value with control which led to weak infection. The concentration 1×109 CFU/ml was violent and fish body can’t resist it