Cat's Eye Snail

Lunella smaragdus

Lunella smaragdus, known as the cat's eye snail, is a marine gastropod characterized by its heliciform shell, which can range in size from 35 mm to 70 mm. The shell is solid and depressed, covered with a strong blackish cuticle that reveals a green color underneath. It typically has 4 to 5 whorls, with the upper whorls displaying spiral sulcations or carinations. The large aperture is oblique and rounded, featuring a pearly white interior. The outer lip is thin and edged in black, while the columella is arched and adorned with a pearly callus. The operculum is deep green and flat, resembling an eye, which is the origin of its common name. This species is endemic to New Zealand and inhabits both intertidal and low subtidal environments, often found on rocky shores and soft substrates, including seaweeds. It is typically located on rocks between low and mid tide around the North, South, and Stewart Islands. Cat's eye snails are usually found at depths shallower than 40 meters, with most occurrences recorded at depths less than 20 meters. Little is documented about the diet and breeding habits of Lunella smaragdus. Encounters with this species during dives can be intriguing due to its distinct shell and operculum, which divers may find appealing for photography. The conservation status of this species is not evaluated, indicating that there is insufficient information available.