Dr. Hanping Wang
Aquaculture Program Leader
Aquaculture team members at The Ohio State University South Centers recently published two papers in top journals within the aquaculture industry.
The first paper deals with the evaluation of genetic variation and gene expression patterns of different strains related to the utilization of soybean meal (SBM) in largemouth bass (LMB). It was published by AQUACUTURE, the No. 1 journal in aquaculture, in March 2020.
In that paper, the team found that genetic variation exists for growth and feed efficiency in LMB fed diets containing both SBM and fishmeal, and genetic improvement may be possible for the trait of feed efficiency. In all the three strains they tested, the growth performance of individuals in the S35 (35% fishmeal replaced by SBM) groups declined when compared with the S0 group, and the specific growth rate and weight gain correlated negatively with dietary levels of SBM.
Genes that were differentially expressed between dietary SBM levels were identified. Transcripts of genes related to insulin-signaling pathway and fatty acid metabolism and biosynthesis were significantly downregulated in the S35 and S50 groups compared to the S0 group. This study provides important information for improving growth and breeding strategies of LBM for the aquaculture industry, which contributes ~0.5 million tons of production globally per year.
The second paper discusses the use of medicinal herb to improve immune responses and stress in Nile tilapia, and was published by Fish and Shellfish Immunology (FSI) in January 2020. FSI is the another of the top-ranked journals in the aquaculture industry.
In this study, the team found that the medicinal herb they used significantly enhanced lysozyme activity and nitrous oxide activities, as well as improved superoxide dismutase, catalase, and glutathione peroxidase activities. Growth performance was also markedly improved. Expression of heat shock protein 70 and interleukin 1 beta genes were significantly upregulated throughout the entire experimental period.
When challenged with bacterium, the mortality of treated groups was significantly lower than the control. Current results prove that medicinal herb has a synergistic effect on immune and stress responses, growth performance, and disease resistance. The findings are important for reducing stress and disease in tilapia, the No. 1 aquaculture species in the world.