About Antalis vulgaris (da Costa, 1778)
Antalis vulgaris, commonly known as the common tusk shell, is a small mollusc that reaches 3 to 6 cm in length, and has a characteristic elephant tusk shape. Its shell is opaque white, and bears closely spaced longitudinal striations on its posterior portion. The anterior aperture, which is located on the thinnest end of the shell, is circular. This aperture is blocked by a septum that has a central pipe with a circular opening. This species is distributed in the marine region stretching from south-western United Kingdom to the western Mediterranean. Common tusk shells have separate sexes. Fertilization happens externally, and produces free-floating planktonic larvae called trochophores.
