Phylogeography of the polychaete Phragmatopoma californica (family Sabellarididae) in the Southern California Bight (SCB)

This study measured the genetic differentiation among populations of Phragmatopoma californica and compared this genetic structuring with another polychaete species (Neries grubei) having a different life history. A total of 234 samples from 13 populations of the sabelleriid polychaete Phragmatapoma californica (Fewkes) from six mainland sites along the southern California coast and two Channel Islands were studied by way of inter simple sequence repeats (ISSRs) to determine genetic diversity, divergence and to estimate gene flow among populations. The results were compared to another polycheate species, Neries grubei which has a shorter larval development than P. californica, reducing potential dispersal and gene flow relative to P. californica. Isolation by distance was not demonstrated by either species, which is in contrast to the significant genetic structuring for both species (FST = 0.171; P < 0.001 for P. californica). The genetic distance values of N. grubei samples ( x¯ = 0.095) were significantly greater than for P. californica samples (x¯ = 0.056; P < 0.001). In contrast to genetic distance values, the FST values were similar between species.