Shells of T. arenarius are irregular, and can reach a length of about 100–200 millimetres (3.9–7.9 in).[2][3]
The diameter of the round opening reach 11–15 millimetres (0.43–0.59 in). The inner surface is smooth and shiny. These shells are cemented onto a hard surface and resemble the calcareous tubes of certain marine worms, for example worms in the polychaete family Serpulidae. The visible part of the body is red with cream markings. The foot of this mollusk is atrophied and it has lost its function of movement.[4]
Distribution
This species can be found in the Mediterranean Sea - Eastern Basin[2] and in the North Atlantic Ocean - European waters.[1]
Linnaeus, C. (1758). Systema Naturae per regna tria naturae, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis. Editio decima, reformata. Laurentius Salvius: Holmiae. ii, 824 pp