سیدجواد حسینی

Green tiger shrimp (Penaeus Semisulcatus) is the most important and abundant of the penaeid family in the Persian Gulf. Two morphologically similar groups of Penaeus Semisulcatus have been identified in the Persian Gulf based on their antenna and body color patterns. In this study ITS-1, as a nuclear marker, was considered for the evaluation of the genetic distance between the two groups. Primers ITSF1 and ITSR1 were used to amplify the full length of the ITS-I. These primers were designed based on 18S RNA and 5.8S RNA of similar species. The electrophoresis of PCR products on agarose gel indicated that ITS-I was larger in size in group 2 sample. Using MEGA6, phylogenetic parameters were estimated based on a 310-330 bp fragments. The results of the analysis of the sequences showed that ITS-I was GC rich and had simple sequence repeats in both groups. GGA was one of the SSR in all the samples. The phylogenetic analysis of the ITS-I region show that the two groups form two distinct clades with genetic divergence of .2-0.9. Compared with other Penaeus species, the two morphological groups are genetically closer. The above data suggest the occurrence two cryptic species in the penaeus semisulcatus.