The common purple snail, also known as Janthina janthina, is from the family of Molluscs and is easily recognizable by its distinctive violet shell, which can reach up to 40mm in width. The shell is light purple on the spire and darker on the ventral side, due to its upside-down position in the water column. The snail has a large head on a flexible neck, with small eyes located at the base of its tentacles.
Common purple snails are holoplanktonic, meaning they live their entire lives floating on the surface of the open ocean. They are typically found in surface waters, often in large groups. In Gozo, they have been spotted near popular dive sites such as the inland sea and Mġarr ix-Xini.
Common purple snails lead a unique pelagic lifestyle, floating on the ocean surface thanks to a raft made of hardened chitin bubbles. This adaptation allows them to drift with ocean currents. They start life as males and later change to females, carrying their eggs until they develop into larvae. Their delicate, paper-thin shells enable them to float, but if they lose their raft, they sink and perish.
The common purple snail is carnivorous, primarily feeding on the medusa stage of cnidarians, such as jellyfish, anemones, and corals. Since they cannot propel themselves, they rely on ocean currents to bring their prey to them.
Predators of the common purple snail include various species of fish and sea birds that hunt at the ocean surface. Their vibrant color may also attract other marine predators.
Divers in Gozo can find common purple snails at dive sites like the Azures Blue Hole and Mġarr ix-Xini. These snails are often found floating in large groups and may become stranded on beaches after strong winds. To learn more about the fascinating marine life you can encounter, explore our exclusive Aquatic Animal Guide.
