Intertidal spiral burrows; Paraonis fulgens and Spiophanes wigleyi in the Minas Basin, Bay of Fundy

On some intertidal fine sands of the Minas Basin, Bay of Fundy, the tubicolous spionid polychate Spiophanes wigleyi coexists with the paraonid polychate, Paraonis fulgens. Paraonis feeds on diatoms buried on bedding planes within the sediment, and produces spiral traces 2-3 cm in diameter. Sediment preferences of both worms seem related to feeding behaviour: population densities of Spiophanes were positively correlated with mean grain size, and …