Table 6.

Results of population expansion tests on the four species. Fu’s F _S, Tajima’s D and mismatch distribution estimate (τ) and the real expansion time (t) with 90 % credibility intervals in parentheses for each species are included. All COI sequences of S. japonica were divided into two groups: northern group and southern group, according to the phylogenetic analyses (See the results in the phylogenetic analysis). Reference: Cellana toreuma, Dong et al. [20]; Sargassum horneri, Hu et al. [36]; Atrina pectinata, Liu et al. [37]. *P < 0.05; **P < 0.01, ***P < 0.001

Gene		Neutrality test		Mismatch distribution
		Fu’s F S	Tajima’s D	τ	t (ka)
Siphonaria japonica
COI	northern group	−25.029***	−2.199*	5.750 (4.094-8.898)	440.9 (313.9-682.4)
	southern group	−26.964***	−2.781***	2.486 (1.361-3.381)	190.6 (104.4-259.3)
Cellana toreuma
COI		−30.175***	−2.497***	3.000 (0.422-3.213)	502.5 (70.7-538.2.)
Sargassum horneri
COIII		−18.353***	−1.531*	1.875 (0.75-3.072)	119.3 (47.7-195.5)
Atrina pectinata
COI		−26.277***	−2.527***	1.648 (1.295-4.086)	170.1 (133.7-421.7)