A tube-living bristle worm whose body consists of two parts: a swollen anterior end with a reduced head and specially formed segments and a narrowed posterior end. The head has numerous active feeding tentacles. Three pairs of bright-red gills are present on the first three segments behind the head. Measures up to 300 mm long. The tube consists of medium-sized to large sand grains with a characteristic fan shape at the top. Several tubes together can form so-called ‘sand reefs’.