Abstract
The production of capture fisheries is decreasing and genetic resources are reducing in aquaculture species due to overexploitation of natural resources. Marker-assisted selection (MAS) is one of the ways to rapidly increase genetic gain for enhancing fish production, by improving important traits. Approximately 37 traits have been analyzed in more than 20 aquaculture species. These traits include about 8 qualitative, 21 quantitative, and 8 threshold traits in various species. However, all of the major traits have not yet been utilized and respective gene still needs to be explored for using in MAS. Furthermore, quantitative/qualitative trait loci (QTLs) associated with fecundity, feed conversion ratio (FCR), and immune–response traits such as red blood cell (RBC), white blood cell (WBC), lymphocytes, monocytes, and hemoglobin need greater attention for investigation. In this article, main traits of aquaculture species have been discussed and other most important traits needing more attention are highlighted. Advanced technology of next-generation sequencing (NGS) has facilitated to develop millions of SNPs markers, convenient and accurate, in a single step. Thus, it will increase the power of QTL identification in Aquaculture species. Furthermore, this knowledge will lead the researchers to investigate the QTLs associated with other remaining traits which need to be emphasized for genetic development.