Tiny Snail Sheds Light On Subterranean Diversity In Eurasia

A snail discovered in the Nodong cave in South Korea provides a glimpse into the ancient subterranean biodiversity in the region.

AsianScientist (Aug. 24, 2015) – In a paper published in ZooKeys, researchers describe a tiny snail which is the only cave-dwelling representative of the family of hollow-shelled snails in the whole of Asia.

First discovered by collector J. S. Lee in the depths of Nodong cave, South Korea, the Koreozospeum nodongense snail suggests a a former pan-Eurasian distribution of cave-dwelling, hollow-spired snails.

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 , published its description in the open-access journal ZooKeys.

K. nodongense belongs to a larger group of ancient cosmopolitan air-breathing relatives known to have been amongst the first snail colonizers 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 harbor these denizens of the dark. Hypotheses made by 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 colonization 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 case for further investigations and discovery of rare biodiversity.

The research team led by Dr. Barna Páll-Gergely from Shinshu University, Japan, used 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 and silicon 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.

The article can be found at: Jochum et al. (2015) A New Member of Troglobitic Carychiidae, Koreozospeum nodongense gen. et sp. n. (Gastropoda, Eupulmonata, Ellobioidea) is Described from Korea.

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Source: Pensoft Publishers.
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