World’s largest campodeid dipluran named after the mythological giant Daidarabotchi

The giant newly described species Pacificampa daidarabotchi, discovered in the Mejiro-do cave, Kyushu, Japan. Photo by Rodrigo Lopes Ferreira.

The insect-like animal is also the first subterranean representative of its family in Japan

Amongst the fauna thriving in the subterranean spaces below the surface of the earth’s crust, the insect-like diplurans and, precisely, those in the campodeid family are one of the best-known groups, currently comprising almost 150 species. However, not a single subterranean member of the family had been known from Japan until very recently.

As part of a project at the National Council of Technological and Scientific Development, the research team of Dr. Rodrigo Lopes Ferreira, Universidade Federal de Lavras, Brasil, and Dr. Kazunori Yoshizawa, Hokkaido University, Japan, conducted an expedition to a total of 11 carbonate caves in the southern Japanese islands of Kyushu and Shikoku. Out of these, they managed to collect dipluran specimens from three touristic sites and sent them to Dr. Alberto Sendra from the Research group in Soil Biology and Subterranean Ecosystems at Alcala University, Spain, for identification.

The Mejiro-do cave, Kyushu Island, Japan: the type locality of the newly discovered record-breaking species Pacificampa daidarabotchi. Photo by Rodrigo Lopes Ferreira.

To the amazement of the scientists, it turned out that they had collected specimens of two previously unrecognised species of well-adapted subterranean campodeid diplurans.

Moreover, one of the new species (Pacificampa daidarabotchi), identified exclusively from the Mejiro-do cave located near an active quarry in Kyushu, proved to be the largest known dipluran in the family Campodeidae. Measuring about 10 mm in length, the creature looks gigantic next to any other campodeid, which, most often, are only half as big.

Inspired by the peculiar size of the former, the researchers decided to name it after the giant yökai creature Daidarabotchi, known from Japanese mythology. According to one of the legends, Daidarabotchi once lifted up the mountains of Fuji and Tsukuba in order to weigh them. By accident, he split the peak of Tsukuba in the process.

Another remarkable finding from the same study is that the genus, where both new species were assigned – Pacificampa – serves as yet another example of the former physical connection between Asia and America some millennia ago. In their paper, the scientists note that the genus demonstrates close affinities with a genus known from North America.

“We hope that this discovery could stop the destruction of the land nearby and preserve for the future the subterranean habitat of these remarkable gigantic species,” say the researchers in conclusion.

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Last year, lead author Dr. Alberto Sendra and his colleagues Prof. Boris Sket, University of Ljubljana, and Prof. Pavel Stoev, National Museum of Natural History, Bulgaria, described another cave-dwelling campodeid dipluran to the world’s amazement.

Discovered in Eastern Turkmenistan, the species, whose name (Turkmenocampa mirabilis) refers to its wondrous peculiarity, was the first of in the order Diplura found in Central Asia. Further, it was the first strictly subterranean terrestrial creature recorded in the country.

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Original source:

Sendra A, Yoshizawa K, Ferreira RL (2018) New oversize troglobitic species of Campodeidae in Japan (Diplura). Subterranean Biology 27: 53-73. https://doi.org/10.3897/subtbiol.27.28575

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

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Additional information:

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