Two new snail species were found in a canyon slated to be flooded by a dam

Two land snails no longer than a grain of rice, Cochlostoma komarnica and Cochlostoma dobrido, have been described from northern Montenegro. One of them takes its name from the Komarnica Canyon, a gorge that a proposed hydropower dam and reservoir would put under water. The other is named for the Dobri Do plateau inside Durmitor National Park, which adjoins the canyon.

The species were collected between 2018 and 2025 on citizen-science expeditions, and their descriptions give conservation campaigners a concrete argument: the canyon that gives one species its name is the same canyon a reservoir would drown, and the gorge is among the places where the animals were collected.

Cochlostoma komarnica and Cochlostoma dobrido on the limestone

The formal description appeared in the Biodiversity Data Journal on 27 July 2026 as “Two new Cochlostoma species from the Durmitor and Komarnica regions of northern Montenegro.” Menno Schilthuizen is the corresponding author, and the paper lists 23 co-authors from several European countries, including the Italian malacologist Enrico Zallot. Both species are placed in the subgenus Turritus, formally written as Cochlostoma (Turritus) dobrido and Cochlostoma (Turritus) komarnica, and both were found living alongside a known relative, Cochlostoma scalariniforme, at some sites.

According to the publisher’s account, the animals live on limestone rock, where they graze algae and lichens. They have conical shells, eyes set on the sides of the head rather than on stalks, and a circular disk on the tail that seals the shell opening like a door when the animal withdraws. That door is the group’s signature: Cochlostoma belongs to a family of land snails with an operculum, a trait that most pulmonate land snails lack.

The genus is a distinctly European one. Cochlostoma snails are members of the Cochlostomatidae, placed in the Caenogastropoda in the paper’s own title, and they live on limestone rock, where bare outcrops can act as islands separated by unsuitable ground. Isolated outcrops can hold lineages of their own, which is how a gorge can contain animals found nowhere else.

Dissection, DNA barcoding and field laboratories

Telling the species apart took more than a hand lens. The authors combined shell measurements, dissection of reproductive anatomy, DNA barcoding and phylogenetic analysis, much of it done in improvised laboratories set up during the expeditions. Species of this kind often go unrecognised because they look alike on the outside, which is why the dissection and the DNA mattered. The expeditions were run by Taxon Expeditions, which pairs professional taxonomists with citizen scientists, local students and conservationists, and by the Montenegrin Ecologists Society.

The paper’s abstract points to why such small animals carry weight: slow-migrating gastropods are key indicators of habitat continuity, meaning areas of relatively long-term ecological stability. Animals that move so slowly cannot be expected to recolonise a drowned gorge from the next valley, which is why their presence in a canyon is read as evidence of long continuity there.

The proposed Komarnica dam and the case against it

The Komarnica dam, a concrete arch structure that reference listings give as roughly 171 metres high, has been proposed for years and is listed with construction suspended. Its reservoir would be among the largest in Montenegro and would cover the canyon floor.

The project has run into trouble before. The same reference listing says construction has been delayed repeatedly, with opponents raising concerns about wolves, bears, eagles and otters, and arguing that the dam conflicts with Article 4(7) of the EU Water Framework Directive, a point that bears on Montenegro’s accession talks. Critics also note that Montenegro’s hydropower output swings with the seasons, so the dam’s roughly 213 gigawatt-hours a year would not remove winter imports of electricity.

Jovana Đokić of the Montenegrin Ecologists Society used the EurekAlert release to press the point. “The rich biodiversity in the canyons, mountains, and gorges of this part of the Balkans is still largely unexplored,” she said. In the account republished by ScienceDaily, she added that “it is all the more worrying that the Komarnica Canyon is targeted to be flooded by a hydropower dam and reservoir,” and that hydropower is “neither green nor sustainable energy when it destroys a unique ecosystem like this.”

The society wants the canyon added to the UNESCO World Heritage site that already protects Durmitor National Park, and wants the dam project abandoned. Janine Buisman, a musician who joined an expedition and is a co-author, said she “was amazed that it is still possible to discover new animal species in Europe.”

The unresolved question is one of status. The Biodiversity Data Journal paper and the releases describe the species and the threat to the canyon, but neither reports a formal conservation assessment for either snail. Until one exists, the species have no listing that a planning authority would have to weigh, and the Montenegrin Ecologists Society is using the new descriptions to build that scientific case.

This article was produced with the assistance of AI and reviewed by Morning Overview editors prior to publication.

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