First records of mass strandings of Janthina species (Gastropoda: Epitoniidae) in Greece and new observations on the early life history and feeding ecology of pelagic violet snails

Abstract In this study, mass strandings of the pelagic violet snails Janthina janthina (Linnaeus, 1758) and Janthina globosa Swainson, 1822, recorded between 2016 and 2026, are documented for the first time in Greece, specifically along the inner (Laconian Gulf-facing) coastline of the Maleas Peninsula in Southern Peloponnesus, Greece. Previous records from the region are largely incidental, typically involving single or few individuals and lacking ecological context. Accompanying strandings of the pleustonic hydrozoans Velella velella (Linnaeus, 1758) and Porpita porpita (Linnaeus, 1758) are also reported. In addition, new information on the early life history and reproductive ontogeny, as well as the feeding behavior of the two species is presented, contributing to a more comprehensive understanding of Janthina snail biology.