5 CONCLUSION
A homogeneous population structure with low genetic diversity and
star-like haplotype pattern was revealed for E. cardinalis in
Beibu Gulf. Furthermore, pairwise comparisons of ΦST and
the effective number of migrants between all sampling sites in Beibu
Gulf indicated a single panmictic stock of E. cardinalis . This is
mainly attributed to the free genetic exchange of E. cardinalisduring reproduction. However, E. cardinalis from the eastern
South China Sea cannot disperse into Beibu Gulf because of the
circulation patterns and ocean geographical features such as the
semi-closed sea of Beibu Gulf. This molecular evidence revealed thatE. cardinalis from Beibu Gulf experienced colonization and
population expansion during the late Pleistocene due to sea level
fluctuations.