(Johnston, 1837)
Description:
Anatomically, this species is very similar to Cephalothrix linearis , however smaller, reaching a length of 50-60 mm or more but only 0.5 mm or less in width (C. rufifrons). The colour is translucent or whitish, with a variable amount of orange, red or bluish-red pigment on the tip of the bluntly rounded head. Occasionally the entire head may exhibit an orange hue.
Well developed parenchymatous connective tissues in the pre-oral regions. Breeding takes place from early spring to late autumn. Newly hatched juveniles possess two small black eyes, but these are soon lost and the adults are eyeless.
Habitat:
Commonly found intertidally beneath stones and boulders, usually in clean coarse sand or shelly sand, less often in black muds. It also occurs among algae, particularly on Corallina in rock pools. In shallow water it may occur on Zostera, but it has also been dredged from sand at depths of 30 m. The species is occasionally found in waters with a reduced salinity, i.e., the lower regions of estuaries.
Distribution:
Known from northern Europe and the Mediterranean. It appears to be fairly common, although it is an inconspicuous species.