Table 5. The results of AMOVA for the hierarchical subdivision of H. japonica in Korea, using 657 base pair (bp) of the COI gene.

Source of variation	d.f.	Sum of squares	% variation
(a) All samples (n = 339)
Among groups	3	314.776	35.21
Among populations within groups	10	119.550	13.98
Within populations	325	543.430	50.81
Total	338	977.755
(b) Mainland samples only (n = 295)
Among groups	2	219.337	32.72
Among populations within groups	10	116.055	12.82
Within populations	282	523.907	54.47
Total	294	859.298

Based on mountain ranges and open sea, the populations of H. japonica in Korea were divided into four groups: western, eastern, southwestern, and Jeju Island. AMOVAs were conducted twice: once using all 339 samples from 16 localities (a) and once using the mainland samples only (b).