Changeable Nassa

Tritia mutabilis

Tritia mutabilis, commonly known as the Changeable Nassa, is a marine gastropod that can be identified by its smooth, ovate, and slightly ventricose shell, which varies in size from 14 mm to 30 mm. The shell features a spire made up of seven whorls, with the lowest whorl being notably larger. Its exterior is typically red or fawn-colored, adorned with an articulated band of white and violet at the upper edge of the whorls, along with longitudinal yellow or red spots. This species exhibits color variations, which can change based on exposure to light. This species inhabits the Mediterranean Sea and the Black Sea, as well as the Atlantic Ocean off Mauritania and West Africa. It prefers a benthic lifestyle, residing in fine well-sorted sand and fine muddy sands at depths ranging from 2 to 50 meters, although most occurrences are shallower than 40 meters. The Changeable Nassa is often found buried in the substrate with its proboscis extended, emerging at night to forage for food. As a scavenger, the Changeable Nassa primarily feeds on detritus-rich substrates when in its juvenile stage, while adults consume small invertebrates. This species does not engage in broadcast spawning and is known to undergo sex reversal from male to female at lengths between 1.8 to 2.0 cm. Encounters with this species during dives can be intriguing, as divers may observe it foraging at night or partially buried in the sand during the day. Its conservation status has not been evaluated.