The animal within the burrow is soft and contractile with obvious red filimentous gills. It has a cluster of long spaghetti like extendable head tentacles, that emerge from the tube and spread widely over the surface of the sediment. A common species is Thelepus plagiostoma

Forms parchment tubes encrusted with coarse shell and sand, in the low intertidal to shallow subtidal.

Feeds on organic detritus at the surface of the sediment. Mud is scooped up by the tentacle tip and passed back along a groove to the mouth.

Jones, M. B., Marsden, I, D., 2005, Life in the Estuary. Canterbury University Press.