Abstract
The genetic differentiation among local populations (GST) was reviewed in 20 decapod crusta-ceans which could be classified into three groups; marine, anadromous, and landlocked. The mean GST values in each group significantly increased in the order of marine (0.039), “anadromous”(0.090), and landlocked (0.228) groups. These variations are mainly contributed to geographic barriers. Distinct GST values, however, were observed even between species within a group (especially marine and anadromous). This suggested that species-specific dispersal ability and migratory character are contributory to the differentiated level of GST among species besides the intensity of geographic barriers.
