Nassarius castus

Nassarius castus is a species of sea snail, a marine gastropod mollusc in the family Nassariidae, the Nassa mud snails or dog whelks.

Description
The length of the shell varies between 17 mm and 41 mm.

Distribution
This species occurs in the Red Sea, in the Indian Ocean off the Mascarene Basin and La Réunion; in the Indo-West Pacific.