Table 2. Fixation indices for the mtDNA CR corresponding to the groups (k) of populations inferred by AMOVA for the 11 areas of sampling.

k	Group composition	FSC	FST	FCT	FSC/FCT
2	[AZ] [MAD+Atlantic+Mediterranean]	0.0166*	0.1219**	0.1070**	0.1551
3	[AZ] [MAD+Atlantic] [Mediterranean]	0.0146*	0.0657**	0.0519**	0.2813
4	[AZ] [MAD] [Atlantic] [Mediterranean]	0.0022	0.0578*	0.0558**	0.0394

Abbreviations: AMOVA, analysis of molecular variance; Atlantic, Canaries Is., Mauritania, Cadiz, Portugal Centre and Portugal South; AZ, Azores Is.; CR, control region; MAD, Madeira Is.; Mediterranean, Malta, Palermo, Balearic Is. and Torre Guaceto; mtDNA, mitochondrial DNA.

F_ST (variance among populations relative to the total variance), F_SC (variance among populations within groups) and F_CT (variance among groups relative to the total variance).

*P<0.05 and **P<0.001.