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.
