Investigation of the possibility of utilizing two mitochondrial gene regions to differentiate two Penaeus species: A preliminary study

Abstract

Black tiger prawn Penaeus monodon and Green tiger prawn P. semisucatus show similar morphological characters up to some extent thus are difficult to differentiate them especially at their larval stages. This preliminary investigation focused on the possibility of utilizing genetic based approach to distinguish the above two Penaeus species. Two mitochondrion gene regions i.e. 12S rRNA and 16S rRNA, were partially amplified using universal primers and sequences were obtained for analysis. For 12S rRNA gene region, the percentage of base composition for P. monodon was A: 34.79%, C: 11.34%, G: 17.78%, T: 36.08% and for P. semisulcatus it was A: 36.36%, C: 13.51%, G: 17.40% and T: 32.73%. For 16S rRNA gene region the percentage of base composition for P. monodon was A: 34.43%, C: 12.70%, G: 18.85%, T: 34.02% and for P. semisulcatus it was A: 33.40%, C: 12.09%, G: 20.70% and T: 33.81%. Genetic distance (p distance) between P. monodon and P. semisulcatus was 18.4% and 8% for 12S rRNA and 16S rRNA gene regions respectively. The utility of restriction enzymes to discriminate these two Penaeus species was investigated and possibility of application of three restriction enzymes on this purpose was determined. P. monodon shows high growth rate compared to P. semisulcatus thus extensively used in aquaculture industry. Therefore, correct identification of two Penaeus species is important when selecting brood stocks and the larval stages from the wild catch for culturing purposes.