(Johnston, 1827-28)
Description:
A slender and cylindrical species, up to 10 cm in length and about 0.2 cm in width. The colour is quite variable, depending on its reproductive state and content of the gut. In general, it is dull pinkish or with dirty white hue, with a paler head, tail and body margins. The body is rounded, slender and gradually tapers towards the bluntly pointed tail. The head is broad but bluntly pointed, with many eyes in two groups on each side. Posterior cephalic furrows meet mid-dorsally as a backward pointed V behind the cerebral ganglia (A. lactifloreus-head).
Habitat:
Locally very abundant on fairly clean sandy or gravelly sediments from just below the Pelvetia zone on the shore to depths of 250 metres or more. It is also found amongst shell debris, on Laminaria , Fucus and Ascophyllum and, less commonly, in silty or muddy substrata. To some extent, it is tolerant of fluctuating salinities.
Distribution:
In the North Sea it is distributed along the English east coast, in the Kattegat and Gullmarfjord. Elsewhere it is distributed from the Mediterranean and northern coasts of Europe to the Atlantic and Arctic coasts of North America, north of Cape Code.