Genetic assessment of the population connectivity of the red urchin (Strongylocentrotus franciscanus)

A set of five microsatellite genetic markers was used to examine connectivity among populations of the red urchin, Strongylocentrotus franciscanus, collected from five locations in California and two locations in British Columbia, Canada. Consistent with previous studies, there was little evidence of differentiation among the California populations. However, significant divergence (FST = 0.039), as well as isolation by distance (IBD) (R2 = 0.2815, p = 0.024), was observed between the California and British Columbia populations. These results show for the first time that, on a range wide scale, populations of red urchins are genetically divergent. Although the detected differentiation is low, it suggests that even the estimated 7–19 month planktonic larval duration of this species fails to homogenize the gene pool across the species range.

► Microsatellites were used to examine the population connectivity of the red urchin. ► Significant population differentiation was found between California and Canada. ► No significant population differentiation was found within California. ► This is the first evidence of isolation by distance in S. franciscanus.