Tag: snail

China’s First Cave-Dwelling Freshwater Snail Named After A Mythical Mountain God

This study marks the first freshwater cave snail ever recorded in China, and it represents the highest-altitude distribution known among cave-dwelling species in the family Erhaiidae.

Recently published in the journal Subterranean Biology, the research marks a major milestone for the study of subterranean aquatic life in East Asia. Prior to this discovery, there were no records of freshwater cave snails within Chinese territory, and the region’s subterranean freshwater mollusks were generally poorly studied.

Mythological Namesake and Unique Adaptations

Perfectly suited to its pitch-black environment, Erhaia dijiang is a true troglobiont, having evolved without eyes entirely while its ocular structures show total degeneration. Its shell is small, conical, and highly translucent, while its body is delicate and unpigmented, with slender tentacles.

Natural habitats of *Erhaia* *dijiang*. Credit to He et al., 2026.

Fittingly, researchers named the species dijiang after “Di Jiang,” a mountain patron god from ancient Chinese mythology described as a faceless beast in the classic text Classic of Mountains and Seas (山海经). The name suits the animal’s habits: in laboratory observations, the snails proved highly photophobic, actively seeking out dark crevices beneath rocks to escape light.

Beyond its mythological namesake, the species is also notable for where it was found. Discovered at an elevation of 2,062 meters, Erhaia dijiang sets a new record for the highest-altitude distribution among all known cave-dwelling snails in Erhaiidae, evidence that freshwater cavesnails can survive in karst caves at altitudes exceeding 2,000 meters.

According to the researchers, the species inhabits underwater gravel and crushed stone at depths of less than one meter, where cave water temperatures remain consistently near 20°C. While rapid water flow during the rainy season occasionally flushes a small number of snails out through the cave’s outlet, they are never found in nearby surface streams and stay strictly within two meters of the cave entrance. In the lab, the snails fed on diatoms growing on rock surfaces as well as artificially supplied fish food.

Urgent Call for Conservation

Erhaia dijiang new cave snail from China — *Erhaia* *dijiang*. Credit to He et al., 2026.

However, despite marking a significant advance for the study of subterranean aquatic life in East Asia, the research team warns that the survival status of this newly discovered species is “far from optimistic.”

During their initial field survey in August 2025, the population density of Erhaia dijiang was found to be extremely low. The team was only able to locate three live adult individuals and a single empty shell in the shallow underground waters, and no juvenile snails were observed.

The researchers are urgently calling for extensive surveys of Chinese caves to improve our understanding of these complex ecosystems, along with the rapid formulation of conservation measures to protect these vulnerable, endemic mollusks.

Original study:

He Y-M, Xiang H-Q, Yang J-M, Zheng H, Yang S-Z, Zhou Y-F, Zheng J (2026) A new eyeless species in Erhaiidae (Gastropoda, Truncatelloidea) from a cave in Yuxi City, Yunnan, China. Subterranean Biology 56: 127-136. https://doi.org/10.3897/subtbiol.56.188075

New Snail Species Bolster Case For Protecting Montenegro’s Biodiversity

Scientists and citizen volunteers discovered two new snail species in northwestern Montenegro, highlighting the region’s hidden biodiversity and bolstering calls to protect Komarnica Canyon within Durmitor’s World Heritage Site instead of building a hydropower plant.

The descriptions of the two new additions to the European snail fauna, named Cochlostoma komarnica and Cochlostoma dobrido, have been published today in the open-access Biodiversity Data Journal.

A Cochlostoma snail crawling in Montenegro – video by Roman Willi | Wildreach Productions.

The elegant snails, which do not yet have English names, have conical shells of around 7 mm long and live on limestone rocks, where they graze algae and lichens. Unlike most land snails, they do not carry their eyes on the end of eye-stalks, but on the sides of their head. And their shells come with a circular disk stuck to the animal’s tail that can close off the shell like a door.

Shells of Cochlostoma komarnica and Cochlostoma dobrido — *Cochlostoma komarnica* (a, b) and *Cochlostoma dobrido* (c, d) – Photos by Enrico Zallot.

The snails were discovered by the teams of Taxon Expeditions, which run real scientific expeditions that anyone can join. Between 2018 – 2025, expeditions in Montenegro were organised as a collaboration of Taxon Expeditions, the non-profit Taxon Foundation, and local partners from the Montenegrin Ecologists Society.

Citizen scientists and researchers from Taxon Expeditions searching for land snails on the Dobri Do Plateau, Durmitor, Montenegro, where Cochlostoma dobrido was discovered. – Photo by Pierre Escobas | Taxon Expeditions.
Participants of the taxon expedition studying snails in the makeshift field lab near the Komarnica Canyon. – Photo by Marjolein Koster.

Mixed teams of international researchers, citizen scientists, local students, and conservationists studied the biodiversity of Durmitor National Park and Komarnica Canyon. The new snails were found at several sites during fieldwork in the rugged mountainous terrain, but their novelty only became clear once they were dissected and genetically analysed in the field laboratory.

Cochlostoma snail crawling in Montenegro – photo by Roman Willi | Wildreach Productions
Cochlostoma dobrido – Photo by Sotiris Kountouras | Taxon Expeditions.

During a voting session at camp, the team decided to name the species after the localities in which they were discovered: “Cochlostoma dobrido,” after the Dobri Do Plateau, which lies between the peaks of Durmitor National Park, and “Cochlostoma komarnica,” after the stunning but unprotected Komarnica Canyon, south of Durmitor.

I was amazed that it is still possible to discover new animal species in Europe.
says musician Janine Buisman from The Netherlands, who joined one of the expeditions and co-authored the paper.

Another author, biologist Jovana Đokić of the Montenegrin Ecologists Society (MES), explains that the rich biodiversity in the canyons, mountains, and gorges of this part of the Balkans is still largely unexplored and undiscovered.

The endangered Komarnica Canyon, Montenegro – Photo by Sotiris Kountouras | Taxon Expeditions.

It is all the more worrying that the Komarnica Canyon is targeted to be flooded by a hydropower dam and reservoir. This will destroy this wild river canyon and all the biodiversity in it, including many species still unknown to science.
Jovana Đokić

Because of these threats, Komarnica Canyon has become a focus for structured biodiversity surveys, part of an effort to build a science-based case for its conservation.

That is why MES is calling for the canyon to be included in the UNESCO World Heritage site of Durmitor and for the hydropower project’s plans to be scrapped.

Hydropower is neither green nor sustainable energy when it destroys a unique ecosystem like this.
says Đokić

Original source:

Schilthuizen M, Boomsma R, Faes S, Jousma M, Buisman J, Lankenau D-H, Kountouras S, van den Broek M, Hemelaar EM, Noomen J, de Vries R, Lopatriello G, Limongi AR, Maestri S, Kamchev P, van Manen S, Khalik MZ, Delledonne M, Đokić J, Mićanović A, Popović J, Njunjić I, Zallot E (2026) Two new Cochlostoma species from the Durmitor and Komarnica regions of northern Montenegro (Caenogastropoda, Cochlostomatidae). Biodiversity Data Journal 14: e196955. https://doi.org/10.3897/BDJ.14.e196955

Tiny new species of snail named after Picasso

Anauchen picasso is among 46 new species of microsnails discovered in Cambodia, Myanmar, Laos, Thailand, and Vietnam.

They say beauty is everywhere if we have eyes to see; a team of scientists looked at a tiny, 3-mm snail and saw art.

An international group of malacologists (researchers studying molluscs) led by Serbian PhD student Vukašin Gojšina and his Hungarian supervisor, Barna Páll-Gergely, was exploring snail diversity in Southeast Asia when a species unknown to science grabbed their attention, prompting them to name it after cubist artist Pablo Picasso.

Unlike most other snails, Anauchen picasso has rectangularly angled whorls that, according to the scientists, make it look “like a cubist interpretation of other snails with ‘normal’ shell shapes.”

A photo showing four views of a translucent, pink spiral snail shell with distinctive ridges and a spiral apex, with a 1-mm scale for reference. — *Anauchen picasso*.

The research team just published a 300-page article including the descriptions of 46 new species of microsnails from Cambodia, Myanmar, Laos, Thailand, and Vietnam.

Close-up of a black and white SEM image revealing a heart-shaped cavity with textured edges, scale bar shows 0.5 mm. — SEM imaging showing an enlarged apertural view of *Anauchen picasso*.

“Although the shell sizes of these snails are less than 5 mm, they are real beauties! Their shells exhibit extraordinarily complexity,” they say. “For example, the aperture (the ‘opening’ of the shell) is armed with numerous tooth-like barriers, which are most probably useful against predators. Furthermore, several of the new species have an aperture that turns upwards or downwards, which means that some species carry their shells upside-down.”

These apertural barriers and the orientation of the last whorl on the shell were among the primary characters that helped the researchers tell different snails apart.

Images A-F show various views and textures of a spiral shell. — Appearance of the last whorl A shouldered B rounded C keeled at the centre of the periphery D keeled above the centre of the periphery E keeled below the centre of the periphery F double keeled.

While many of these new species were collected recently, several, unknown to science until now, were found in the collection of the Florida Museum of Natural History, collected all the way in the 1980’s. It is likely (and in some cases, certain) that the locations where these snails were found have already been destroyed by deforestation and limestone quarrying, which are the major threats to locally endemic land snails in Southeast Asia.

Research article:

Gojšina V, Hunyadi A, Sutcharit C, Tongkerd P, Auffenberg K, Grego J, Vermeulen JJ, Reischütz A, Páll-Gergely B (2025) A new start? Revision of the genera Anauchen, Bensonella, Gyliotrachela and Hypselostoma (Gastropoda, Eupulmonata, Hypselostomatidae) of Southeast Asia with description of 46 new species. ZooKeys 1235: 1-338. https://doi.org/10.3897/zookeys.1235.145281

Novak Djokovic now has a tiny new snail species named after him

Do freshwater snails make good tennis players? One of them certainly has the name for it.

Enter Travunijana djokovici, a new species of aquatic snail named after famous Serbian tennis player Novak Djokovic.

Photo of Tavunijana djokovici, a new snail species from Montenegro named after Serbian tennis player Novak Djokovic. Photo by J. Grego

Slovak biospeleologist Jozef Grego and Montenegrin zoologist Vladimir Pešić of the University of Montenegro discovered the new snail in a karstic spring near Podgorica, the capital of Montenegro, during a field trip in April 2019. Their scientific article, published in the open-access, peer-reviewed journal Subterranean Biology, says they named it after Djokovic “to acknowledge his inspiring enthusiasm and energy.”

“To discover some of the world’s rarest animals that inhabit the unique underground habitats of the Dinaric karst, to reach inaccessible cave and spring habitats and for the restless work during processing of the collected material, you need Novak’s energy and enthusiasm,” the researchers explain.

T. djokovici has a milky-white shell in the shape of an elongated cone and is adapted to live in the underground habitats of the Dinaric karst. It is part of Hydrobiidae, a very diverse family of small to tiny snails – also known as mud snails – inhabiting fresh or brackish water, including caves and subterranean habitats.

The type locality where Tavunijana djokovici was found.

This is the first member of the genus Travunijana so far to be discovered in the Skadar Lake basin, and the only one found outside of the Trebišnjica river basin in Herzegovina, which points to the enigmatic distributional range of these snails across the Dinaric underground habitats. Where they came from, and how, remains a mystery.

Because of its small area of occupancy, T. djokovici is assessed as Vulnerable, according to the IUCN Red List of Threatened Species. Subterranean ecosystems, the authors of the new species emphasise, are extremely vulnerable to human-driven environmental changes, and, being obscure, they’re often overlooked during conservation efforts.

Original source:

Grego J, Pešić V (2021) First record of stygobiotic gastropod genus Travunijana Grego & Glöer, 2019 (Mollusca, Hydrobiidae) from Montenegro. Subterranean Biology 38: 65–76. https://doi.org/10.3897/subtbiol.38.64762

Huge organs defy austerity for tiny cave snails in the subterranean realm

While most of the knowledge about tiny snails comes from studying empty shells sifted out from piles of dust and sand, the present research is the first contemporary microscopic exploration of organs in cave snails tinier than 2 mm. The paper, published in the open-access journal Subterranean Biology, reveals that underneath the seemingly fragile shells of the Zospeum genus, there are strikingly huge organs.

A number of remarkable observations such as an enormous kidney, grooved three-pointed teeth and a huge seasonally present penis are reported in the recent study, conducted by Adrienne Jochum, Naturhistorisches Museum der Burgergemeinde Bern, Switzerland, and her international team of researchers from University of Bern, Switzerland; Shinshu University, Japan; Universitaetsklinikum Giessen und Marburg GmbH, Germany; Justus-Liebig University Giessen, Germany; University of Ljubljana, Slovenia; University of Bern Goethe-University Frankfurt, Germany; Ruhr University Bochum, Germany; Croatian Biospeleological Society, Croatia and University Duisburg-Essen, Germany.

The scientists describe these characteristics as adaptations the miniature creatures have acquired in order to survive austerity in the subterranean realm.

Usually, adaptations to cave life can include blindness or lack of eyes, loss of pigmentation, sensitivity to changes in temperature and humidity, a high starvation tolerance, or anatomical compromises such as small size and transparent shells. The present study shows that miniscule carychiid subterranean snails have developed huge organs to tolerate the unique conditions of cave life.

“Studying adaptations in extreme environments such as those found in snails of subterranean habitats can help us to understand mechanisms driving evolution in these unique habitats,” explains the first author.

Glassy cave-dwelling snails known only from Northern Spain, the southern Eastern Alpine Arc and the Dinarides might have tiny hearts, but their enormous kidney extends from one to two thirds of the total length of their minute shells. This phenomenon could be explained as an effective mechanism used to flush out large amounts of excess water during flooding seasons in caves.

The same impressive creatures have also developed elaborate muscular plates, forming the girdle that surrounds the gastric mill (gizzard) in their digestive tract. The muscular gizzard grinds the grainy stew of microorganisms and fungi the snails find in moist cave mud. These mysterious creatures graze stealthily using an elastic ribbon (radula), aligned with seemingly endless rows of three-pointed, centrally-grooved teeth, as they glide through the depths of karst caves while searching for food and partners.

Deprived from the hospitable aspects of life we have grown used to, some of the snails discussed in the present paper have evolved their reproductive system in order to be able to reproduce in the harshest of environments, even when they fail to find a partner for an extended period of time.

As a result, not only are these snails protandric hermaphrodites, meaning that they possess male sexual features initially, which later disappear so that the female phase is present, but they have a large retractable, pinecone-shaped penis for instantaneous mating in the summer when mating is most probable. To guarantee offspring, a round sac, known as the receptaculum seminis, stocks sperm received from a partner during a previous mating and allows them to self-inseminate if necessary.

Teeth in these cave snails are also described using histology for the first time. They bear a median groove on the characteristic cusps known for the Carychiidae.

Sketchy, past dissections provide the current knowledge upon which the findings from this investigation are based. Otherwise, historical descriptions of these tiny snails are only known from empty shells found in samples of cave sediment. The genus Zospeum can only be found alive by inspecting cave walls using a magnifying glass.

“Knowledge of their subterranean ecology as well as a “gut feeling” of where they might be gliding about in their glassy shells is necessary to find them,” comments Adrienne Jochum. The authors also emphasize that this groundbreaking work is important for biodiversity studies, for biogeographical investigations and for conservation management strategies.

Adrienne Jochum and her team investigated the insides of the shells using nanoCT to differentiate species in synchronization with molecular approaches for genetic delimitation. Four well-defined genetic lineages were determined from a total of sixteen Zospeumspecimens found in the type locality region of the most common representative, Zospeum isselianum. This investigation is the first integrative study of live-collected Zospeum cave snails using multiple lines of data (molecular analyses, scanning electron microscopy (SEM), nano-computer tomography (nanoCT), and histology.

This work is dedicated to the industrious Slovenian malacologist Joze Bole, whose work greatly inspired the present research.

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Original source:

Jochum A, Slapnik R, Klussmann-Kolb A, Páll-Gergely B, Kampschulte M, Martels G, Vrabec M, Nesselhauf C, Weigand AM (2015) Groping through the black box of variability: An integrative taxonomic and nomenclatural re-evaluation of Zospeum isselianum Pollonera, 1887 and allied species using new imaging technology (Nano-CT, SEM), conchological, histological and molecular data (Ellobioidea, Carychiidae). Subterranean Biology 16: 123-165. doi: 10.3897/subtbiol.16.5758

Tiny, record-breaking Chinese land snails fit almost 10 times into the eye of a needle

Minuscule snails defy current knowledge and scientific terminology about terrestrial “microsnails”. While examining soil samples collected from the base of limestone rocks in Guangxi Province, Southern China, scientists Barna Páll-Gergely and Takahiro Asami from Shinshu University, Adrienne Jochum, University and Natural History Museum of Bern, and András Hunyadi, found several minute empty light grey shells, which measured an astounding height of less than 1 mm.

The single known shell of Angustopila dominikae, named after the wife of the first author, was measured a mere 0.86 mm in shell height. Thus, it is considered to be perhaps the World’s smallest land snail species when focusing on the largest diameter of the shell. With very few reported instances of species demonstrating this degree of tininess, the team have described a total of seven new land snail species in their paper, published in the open access journal ZooKeys.

Another of the herein described new species, called Angustopila subelevata, measured 0.83-0.91 mm (mean = 0.87 mm) in height.

Two of the authors have previously described other species of tiny land snails from China and Korea in the same journal.

In their present paper, Dr. Pall-Gergely and his team also discuss the challenges faced by scientists surveying small molluscs, since finding living specimens is still very difficult. Thus, the evolutionary relationships between these species, as well as the number of existing species are yet little known.

“Extremes in body size of organisms not only attract attention from the public, but also incite interest regarding their adaptation to their environment,” remind the researchers. “Investigating tiny-shelled land snails is important for assessing biodiversity and natural history as well as for establishing the foundation for studying the evolution of dwarfism in invertebrate animals.”

“We hope that these results provide the taxonomic groundwork for future studies concerning the evolution of dwarfism in invertebrates,” they finished up.

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Original source:

Páll-Gergely B, Hunyadi A, Jochum A, Asami T (2015) Seven new hypselostomatid species from China, including some of the world’s smallest land snails (Gastropoda, Pulmonata, Orthurethra). ZooKeys 523: 31-62. doi: 10.3897/zookeys.523.6114

Cave snail from South Korea suggests ancient subterranean diversity across Eurasia

As tiny as 1.7 mm, a snail whose relatives live exclusively in the deep recesses of caves, provided a sensational discovery from the depths of Nodong cave, South Korea, back in 2000 for its collector, J. S. Lee. It is the only cave-dwelling representative of the family of hollow-shelled snails in the whole of Asia with its closest relatives known from as far as Croatia and Northern Spain. The scientists, Adrienne Jochum, Bern University and Natural History Museum Bern, Larisa Prozorova and Mariana Sharyiool from the Far Eastern Russian Academy of Sciences and Barna Páll-Gergely from Shinshu University, published its description in the open-access journalZooKeys.

The Asian species has awaited 15 years to come out of the dark for a name and into the limelight of subterranean biodiversity and conservation awareness. This barely visible snail suggests a former pan-Eurasian distribution of cave-dwelling, hollow-spired snails.

The tiny-shelled treasure, called Koreozospeum nodongense, belongs to a larger group of ancient cosmopolitan air-breathing relatives known to have been amongst the first snail colonisers of land via mangroves about 65 million years ago. Similar to its European relatives from the genus Zospeum, the South Korean snail was also found on muddy cave walls.

Although more than 1,000 caves have been explored in South Korea, Nodong is so far the only one to harbour these beautiful denizens of the dark. Hypotheses made by Culver et. al. in 2006 about the existence of a very narrow, mid-latitudinal ridge of subterranean biodiversity (ca. 42-46°N in Europe and 33-35°N in North America) might clarify this unique find.

A high amount of caves known to exist within these latitudes provide ample habitats for colonisation of life. If this hypothetical ridge were to be extended further East away from Europe, then Koreozopseum‘s gliding along walls in a South Korean cave (33-35°N) makes a strong call for further investigations and discovery of rare biodiversity.

Jochum and her international team described K. nodongense using computer tomographic scans (Nano-CT) in a video film to view and compare the contours and architecture of the very fragile shell. Chemical trace elements, such as aluminum (Al) and silicon (Si) were detected in other scans of the thin diaphanous shell using mineralogical analysis techniques (SEM-EDX). These elements may play a role in the biomineralization (hardness) of the shell or may be contaminants absorbed by the snail from sediment consisting of volcanic ash from former eruptions in the region.

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Original Source:

Jochum A, Prozorova L, Sharyi-ool M, Páll-Gergely B (2015) A new member of troglobitic Carychiidae, Koreozospeum nodongense gen. et sp. n. (Gastropoda, Eupulmonata, Ellobioidea) is described from Korea. ZooKeys 517: 39-57. doi: 10.3897/zookeys.517.10154

Additional information:

The Naturhistorisches Museum der Burgergemeinde Bern, Switzerland and the Far Eastern Branch of the Russian Academy of Sciences supported this work.

Brushing off the dust: New snail species found lying in a museum since the 19th century

Having been collected back in the 19th century during an expedition in South America, a rather small snail species has been sitting around on the shelves of Madrid’s National Museum of Natural Sciences ever since. Covered in more than a century-old dust, it was described as new only recently when an obscure specimen placed in the long tail of a historical collection drew the attention of Drs. Breure and Araujo. Their research is now published in the open-access journal ZooKeys.

The small snail species, called P. cecepeus, had been staying ‘undercover’ for more than a century and a half among the numerous specimens, that formed a total of 20 new species when they were gathered during the historical ‘Comisión Científica del Pacífico’ expedition in South America. With the average undescribed museum invertebrate’s ‘shelf life’ being 20.7 years, it comes as no surprise that the herein described mollusc attracted the attention of the scientists.

Other than its moderately small size, the new species has been characterised with an irregular shape and narrow reddish-brown streaks running vertically across the shell. The surface is rather glossy and coloured in light chestnut-brown.

Although it has been accepted that the snail was found in Ecuador, the authors argue that the locality is “unfortunately very imprecise,” given the data supplied by the collectors. Therefore, the researchers suggest that additional field work should be done in the area so that the “true home” of their discovery is finally recorded.

“Although description of new species that have remained unnoticed for more than a century remains a rare event, it highlights the need for revisions of museum collections and especially the historical parts of these,” conclude the researchers.

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Original source:

Breure ASH, Araujo R (2015) A snail in the long tail: a new Plekocheilus species collected by the ‘Comisión Científica del Pacífico’ (Mollusca, Gastropoda, Amphibulimidae). ZooKeys 516: 85-93. doi: 10.3897/zookeys.516.10228