Information on the population genetics of shrimp species in the Persian Gulf is scarce. There are few electrophoretic based study therefore the aim of the present study was to investigate genetic variation among population of the green tiger prawn, P. semisulcatus, in Bushehr waters, Persian Gulf (Rezvani et al., 2001 and Rezvani, 2002) . This is the first study on this species by RAPDs in this area. The input of research in the field of genetics has resulted in new technological advances that have improved the economic gains of shrimp production.

A total of 50 P. semisulcatus were collected by R/V Lavar II from two major shrimp localities, Halaileh and Daylam, in August and September 2004. Genomic DNA was extracted from muscles using the modified mini preparation method (Lie et al., 1999). A set of 9 primers (Diotech MWG) were used to detect polymorphism among populations. The software package RAPDistance (Armstrong et al., 1994) version 1.04 was used to analyse the data.