Table 3.

Base composition of 17 mayfly mitochondrial genomes, with a greater separation of each of the three Mitogenome-PGC-rRNA-CR groups and separate underlining to mark the three different groups.

Species Name	Mitogenome-PGC-rRNA-CR
	A + T (%)				AT-Skew				GC-Skew
Afronurus furcata	64.5	64.4	64.9	56.9	0.005	−0.198	−0.024	0.23	−0.215	−0.004	0.339	−0.16
Afronurus rubromaculata	64.5	64.6	65.0	65.9	0.009	−0.193	−0.025	0.23	−0.218	−0.010	0.327	−0.11
Afronurus sp. 07BF85	63.3	62.8	65.5	60.0	−0.03	−0.210	0.032	0.02	−0.16	−0.012	0.284	0.05
Afronurus sp. 07BF86	64.0	64.4	65.7	54.1	−0.006	−0.191	0.02	0.13	−0.202	−0.017	0.310	0.02
Afronurus sp. 07BF96	62.9	62.4	65.3	/	−0.027	−0.213	0.035	/	−0.16	−0.010	0.288	/
Afronurus sp. YW01BF06	64.6	64.7	64.4	/	0.012	−0.186	0.002	/	−0.225	−0.010	0.317	/
Afronurus sp. LS53BF04	63.3	63.3	64.7	60.1	0.012	−0.198	−0.022	0.16	−0.227	−0.010	0.329	−0.30
Afronurus yixingensis	65.0	65.1	66.0	63.2	0.003	−0.203	−0.002	−0.01	−0.218	−0.004	0.305	−0.21
Epeorus dayongensis	64.8	64.2	66.1	73.6	0	−0.191	0.012	0.04	−0.212	−0.024	0.269	0.01
Epeorus sp. LA03FY06	67.1	66.3	67.6	77.8	−0.014	−0.188	0.02	0.00	−0.24	−0.003	0.307	−0.19
Leucrocuta aphrodite	65	65.0	65.1	65.4	−0.001	−0.187	−0.001	0.02	−0.186	−0.001	0.284	−0.18
Maccaffertium mediopunctatum	61.7	61.5	60.7	65.9	−0.002	−0.190	0.015	0.02	−0.178	−0.045	0.234	−0.35
Maccaffertium modestum	61.3	61.1	60.7	64.0	0.004	−0.191	0.025	0.01	−0.177	−0.038	0.231	−0.33
Maccaffertium vicarium	62.3	62.3	61.8	65.4	0.005	−0.169	0.013	0.00	−0.172	−0.046	0.253	−0.25
Stenacron interpunctatum	59.7	59.5	58.8	61.7	0.021	−0.184	0.007	0.05	−0.19	−0.057	0.266	−0.24
Stenonema femoratum	62.1	61.9	61.1	66.4	0.005	−0.190	−0.011	0.01	−0.166	−0.039	0.234	−0.30
Heptageniidae sp. YW03BF02	64.2	64.1	64.3	68.5	−0.006	−0.191	−0.011	−0.09	−0.183	0.002	0.27	−0.19