Table 2. Mitochondrial genomes used in analyses.

Order	Family	Species	Gender	Accession number	Reference
Unionoida	Unionidae	Solenaia carinatus	F	KC848654	This study
			M	KC848655	This study
		Lampsilis ornata	F	NC_005335	Serb & Lydeard, 2003
		Unio pictorum	F	NC_015310	Soroka et al., 2010
		Cristaria plicata	F	NC_012716	Jiang et al., 2010
		Anodonta woodiana	F	HQ283346	Soroka, 2010
		Hyriopsis schlegelii	F	NC_015110	Lin et al. Unpublished
		Hyriopsis cumingii	F	NC_011763	Zheng et al. Unpublished
		Unio japanensis	F	AB055625	Okazaki. Unpublished
			M	AB055624	Okazaki. Unpublished
		Pyganodon grandis	F	NC_013661	Breton et al., 2009
			M	FJ809755	Breton et al., 2009
		Venustaconcha ellipsiformis	F	FJ809753	Breton et al., 2009
			M	NC_013659	Breton et al., 2009
		Quadrula quadrula	F	NC_013658	Breton et al., 2009
			M	FJ809751	Breton et al., 2009
		Utterbackia peninsularis	F	HM856636	Breton et al., 2011
			M	NC_015477	Breton et al., 2011
		Utterbackia imbecillis	H	NC_015479	Breton et al., 2011
		Toxolasma parvus	H	NC_015483	Breton et al., 2011
		Lasmigona compressa	H	NC_015481	Breton et al., 2011
	Margaritiferidae	Margaritifera falcata	H	NC_015476	Breton et al., 2011
Mytiloida	Mytilidae	Mytilus edulis	F	NC_006161	Boore et al., 2004
			M	AY823624	Breton et al., 2006

F-female, M-male, H-hermaphrodite (hermaphroditic F-like haplotype)