Thousands of years ago, according to Greek myth, the nymph Cyllena nurtured the infant Hermes, messenger of the gods and famously the swiftest of the twelve Olympians, on Mt. Kyllini in southern Greece.
Now, in that same mountain, researchers from the National and Kapodistrian University of Athens have identified a completely new genus and species of subterranean freshwater snail living in a single isolated spring on its slopes. In a fitting nod to the area’s mythology, and perhaps a bit of irony, given the messenger god’s legendary speed, they named it Cyllena hermes.
The full details of the discovery have been published as a research article in Subterranean Biology, a peer-reviewed open-access journal published by the International Society for Subterranean Biology.
So far, the snail is known from just one place on Earth: a karstic spring roughly 610 meters up the mountain’s foothills, in the Korinthia region of the Peloponnese. There, groundwater seeps out of carbonate bedrock and forms a small stream that feeds toward Lake Stymphalia, part of the sprawling underground hydrological network beneath the Stymphalia closed karst basin.
Type locality of Cyllena hermes gen. et sp. nov., Korinthia, Peloponnese, Greece. Karstic spring waters emerging from Mt Kyllini and forming a stream flowing toward Lake Stymphalia. Credit to Radea et al., 2026
Because the snail relies entirely on this single, isolated water source, it is highly sensitive to environmental stressors such as prolonged droughts and water extraction for surrounding neighboring areas, leading the research team to classify the species as Vulnerable under the IUCN Red List criteria.
When establishing this new monotypic genus and species, the researchers chose a name steeped in ancient Greek mythology tied to the mountain itself. The genus honours Cyllena, the nymph who raised Hermes there, while the species name pays tribute to Hermes himself, who legend says was born in a cave on that same mountain, where the new snail species was found.
This significant finding highlights the rich, yet often undocumented biodiversity dwelling within Greece’s extensive underground karst ecosystems, while also bringing attention to the fragile nature of these highly localized environments.
Original source:
Radea C, Protopapas D, Parmakelis A, Koskeridou E (2026) From the dark to the light: A new genus and species of stygobiont hydrobiid (Caenogastropoda, Truncatelloidea) from southern Greece. Subterranean Biology 57: 1-21. https://doi.org/10.3897/subtbiol.57.189090