(Müller, 1776)
Description
External appearance
Solitary. Body ovoid, usually attached by the base and about 50-130 mm in length. Test cartilaginous, greyish with rough, finely papillated surface.
Characters
Oral siphon with 6-8 lobes and placed terminal; atrial siphon 6-lobed and located about 1/3 of body length away from oral siphon. Not more than 40, well-separated, simple branchial tentacles, always fewer then the number of inner longitudinal vessels. Branchial sac with numerous rows of straight stigmata; no folds; no papillae at intersections of longitudinal and transverse vessels. Gut left of branchial sac; stomach with longitudinal folds. Ovary on the left side of the intestinal loop; testes on both sides (A. aspersa morphology).
Habitat
Attached to hard substrata; from low water level to about 90 metres;
Distribution
From Norway to the Mediterranean.