Wavy Turban

Megastraea undosa

Wavy Turban Snails are among the largest gastropod shells found along the Southern California coast, with sizes ranging from 40 mm to 145 mm. They have a distinctive turbinate-conical shape, characterized by a lack of umbilicus and a dark brown shaggy periostracum covering their shell. The outer edge of each whorl features a twisted ridge, and the surface is adorned with coarsely sculpted rows of fine knobs and folds. The operculum is unique, displaying four strong ridges and hard shelly bristles that radiate from its edge. These snails inhabit rocky shores in shallow waters, typically found in protected areas below the low tide level. Their distribution extends from California, USA, to Central Baja California, Mexico, within the eastern Pacific Ocean. They are commonly located in kelp beds and rocky reefs at depths ranging from 1 to 21 meters, although they can be found as deep as 100 meters. Wavy Turban Snails are herbivorous, primarily feeding on giant kelp and various fleshy and calcareous macroalgae. They reproduce through a process of broadcast spawning, where embryos develop into planktonic trocophore larvae before maturing into juvenile veligers. Diving encounters with Wavy Turban Snails can be interesting, as their large and uniquely shaped shells make them stand out against the rocky substrate. Observing their feeding habits among kelp forests can provide insight into their ecological role. The conservation status of this species is not evaluated.