Mediterranean Bonnet Snail

Semicassis undulata

Semicassis undulata is a medium-sized sea snail found in the Mediterranean Sea and the Atlantic Ocean off Northwest Africa and the Macaronesian Islands. This species can be distinguished from similar species by its unique shell shape and texture, which is characteristic of the helmet and bonnet snails in the subfamily Cassinae. The shell typically features a distinct pattern that aids in identification during dives. This species inhabits a demersal environment, often residing on the sea floor at depths primarily shallower than 130 meters. Approximately 39% of recorded occurrences are found at depths shallower than 40 meters, making it accessible for divers in various locations. The Mediterranean bonnet snail prefers habitats such as rocky reefs and sandy bottoms, where it can find food and shelter. Semicassis undulata is known to be a gonochoric species that reproduces through broadcast spawning. The life cycle begins with embryos developing into planktonic trocophore larvae before maturing into juvenile veligers and eventually becoming adults. Encounters with this species during dives can be intriguing, as divers may observe them foraging on the sea floor, contributing to the local marine ecosystem. The conservation status of this species is currently listed as Not Evaluated, indicating that further research may be needed to assess its population health.