Life-history evidence for sibling species in Axiothella rubrocincta (Polychaeta: Maldanidae)

Individual Axiothella rubrocincta Johnson on the Californian coast live in U-shaped tubes, feed on the surface of the sediment, attain densities of 100 m^-2, attain lengths of 140 mm, have maximum oocyte diameters of 220 μm and produce demersal larvae. Individuals from Washington populations live in vertical tubes, feed 10–15 cm below the sediment surface, reach densities of 5000 m^-2, attain lengths of 60 mm, have maximum oocyte diameters of 385 μm and brood their young in their tubes to at least the 7-setiger stage. Individuals from California have a scalloped posterior margin of the cephalic plate, while individuals from Washington have entire margins. There are no other consistent morphological differences between populations. The population from Eagle Cove, Washington has individuals similar in size and oocyte diameter to individuals from California, but which maintain vertical tubes. A. rubrocincta represents a sibling species complex.