Map of localities.

<p>Localities analyzed of the species <i>Sterechinus neumayeri</i> in Antarctica.</p

Networks for each area.

<p>Median-joining haplotype networks and the distribution of mean number of pairwise differences (mismatch) for each area included in the analyses. *To compare among areas, 18 individuals were randomly selected from the Antarctic Peninsula.</p

Permutation test between regions by locus for two data sets.

<p>Permutation test between regions by locus for two data sets.</p

Historical demographic trends.

<p>Historical demographic trends of effective population size (Ne) constructed using a Bayesian skyline plot approach based on COI haplotypes of <i>S</i>. <i>neumayeri</i>, with two mutation rates (5.1% and 7.2%). The y-axis is the product of effective population size (Ne) and generation length in a log scale while the x-axis is the time in 10³ before present. The median estimate (solid black line) and 95% highest probability density (HPD) limits (gray/pink area) are shown. The thick dashed line represents the time of the most recent ancestor (trcma) and the thin dashed line represents time for the expansion in the species.</p

Description of the microsatellite loci used in the study.

<p>Description of the microsatellite loci used in the study.</p

Schematic representation of the Indian Ocean surface circulation.

<p><i>(a)</i> During the southwest (July/August) and <i>(b)</i> northeast (December/January) monsoon after Schott and McCreary <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0043499#pone.0043499-Schott2" target="_blank">[67]</a>, in relation to crown-of-thorns starfish sampling locations (yellow circles: NIO sister-species, blue circles: SIO sister-species). Blue shaded areas indicate the area in which COTS larvae would likely be released according to season. Green wedges in <i>(a)</i> are upwelling areas. Current branches indicated are the South Equatorial Current (SEC), Southeast and Northeast Madagascar Current (SEMC and NEMC), East African Coast Current (EACC), Somali Current (SC), Ras al Hadd Jet (RHJ), West and East Indian Coast Current (WICC and EICC), Southwest and Northeast Monsoon Current (SMC and NMC), South Java Current (SJC).</p

Characterization of the genetic diversity of <i>Sterechinus neumayeri</i> for West and East Antarctic regions.

<p>Characterization of the genetic diversity of <i>Sterechinus neumayeri</i> for West and East Antarctic regions.</p

Network.

<p>General median joining haplotype network including 174 <i>Sterechinus neumayeri</i> mtDNA COI sequences. Each haplotype is represented by a colored circle indicating the main area where it was collected and the size of the circle is proportional to its frequency in the whole dataset. ° = median vector (theoretical haplotype that has not been collected but should exist).</p

AMOVA results for the Southern and Northern Indian Ocean sister-species.

1<p><i>west</i>: UAE, Oman; <i>central</i>: Maldives; <i>east</i>: Thailand, Aceh, Christmas Island, Pulau Seribu, Krakatau, Karimunjawa.</p>2<p><i>prov19</i>: UAE, Oman; <i>prov20</i>: Kenya, South Africa, Mayotte, South Madagascar, North Madagascar, Réunion, Mauritius; <i>prov22</i>: Chagos; <i>prov27</i>: Cocos Keeling Islands.</p><p>Significance tested with 50,000 permutations; *p<0.05, **p<0.01 and ***p<0.001.</p

Migration matrix of the two most supported gene flow models in the Northern Indian Ocean sister-species (M₃ and M₁; Fig. 2).

<p>Θ_i (diagonal) and the number of migrants from regional grouping i to j per generation, followed by the migration rates in brackets. Top numbers are the results for the asymmetrical model M₃, bottom numbers for the full exchange model M₁.</p