Tag: troglobites

The first cave-bound mollusc species from the Americas

Against the odds, a study by Brazilian researchers describes a new to science species of evidently cave-bound – or troglobitic – clam from northern Brazil.

Exclusively subterranean bivalves – the group of molluscs comprising clams, oysters, mussels, scallops – are considered a rarity. Prior to the present study, there had only been three such species confirmed in the world: all belonging to a small-sized mussel genus known from southeastern Europe. Furthermore, bivalves are not your typical ‘underworld’ dweller, since they are almost immobile and do not tolerate environments low in oxygen. 

Against the odds, a recent study by Dr. Luiz Ricardo L. Simone (Museum of Zoology of the University of São Paulo) and Dr Rodrigo Lopes Ferreira (Federal University of Lavras), published in the open-access scholarly journal Subterranean Biology, describes a new to science species of evidently cave-bound – or troglobitic – clam from northern Brazil. 

Small individuals of the newly described clam species Eupera troglobia sp. n. exposed to the air, next to a harvestman (Eusarcus sp.). Photo by Rodrigo Lopes Ferreira.

Named Eupera troglobia, the mollusk demonstrates features characteristic for organisms not meant to see the daylight, including lack of pigmentation, reduced size, delicate shell and fewer, yet larger eggs.

Curiously, it was back in 2006 when a report presenting a faunal survey of a cave in northern Brazil featured photographs of what was to be described as Eupera troglobia. However, the evidence was quickly dismissed: the clam must have been carried into the cave by water. 

A submerged specimen of the newly described cave-bound clam species Eupera troglobia sp. n.

In 2010, Dr Rodrigo Lopes Ferreira accessed the report and noticed the depigmentation of the clams. Wondering whether it was indeed possible that he was looking at a troglobite, he searched amongst the collected specimens from that study, but could not find any of the discoloured bivalve.

Ten years later, his team visited the cave to specifically search for depigmented shells. Although the cave was partially flooded, the researchers were able to spot the specimens they needed attached to the walls of the cave.

In conclusion, the scientists highlight that their discovery is the latest reminder about how important the conservation of the fragile subterranean habitats is, given the treasure troves in their holdings. 

Meanwhile, recently amended laws in Brazil put caves at considerably higher risk.

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Research paper: 

Simone LRL, Ferreira RL (2022) Eupera troglobia sp. nov.: the first troglobitic bivalve from the Americas (Mollusca, Bivalvia, Sphaeriidae). Subterranean Biology 42: 165-184. https://doi.org/10.3897/subtbiol.42.78074

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King of the Cave: New centipede on top of the food chain in the sulphurous-soaked Movile

A new species of endemic, troglobiont centipede was discovered by an international team of scientists in the Romanian cave Movile: a unique underground ecosystem, isolated several millions years ago during the Neogene, whose animal life only exists because of the chemosynthetic bacteria. As the largest Movile’s inhabitant, the new species can easily be crowned as the ‘king’ of this ‘hellish’ ecosystem. Aptly named Cryptops speleorex, the cave-dweller is described in the open-access, peer-reviewed journal ZooKeys.

A photo of the newly discovered species (Cryptops speleorex), the largest inhabitant of the Movile cave (Romania) known to date
Photo by Mihai Baciu

Deemed to never see the light of the day, a new species of endemic, troglobiont centipede was discovered by an international team of scientists in the Romanian cave Movile: a unique underground ecosystem, where the oxygen in the air might be half of the amount of what we’re used to, yet the sulphurous abounds; and where the animal life only exists because of chemosynthetic bacteria feeding on carbon dioxide and methane.

This hellish ecosystem–where breathing alone could be lethal for most of us–seems to have finally crowned its king. At a size of between 46 and 52 mm in length, the centipede Cryptops speleorex is the largest of the cave’s inhabitants known to date. The new species is described in the open-access, peer-reviewed journal ZooKeys.

Already isolated from the outside world several millions years ago during the Neogene, the Movile cave has been drawing the attention of scientists ever since its unexpected discovery in 1986 by Romanian workers, searching for locations suitable for building a power plant in the southeastern parts of the country.

Surprisingly enough, despite its harsh living conditions, the Movile ecosystem was soon found to harbor a diverse and unique fauna, characterised by exceptional species endemism and specific trophic links. So far, the cave has been known to give home to the troglobiont water scorpion, liocranid and nesticid spiders, cave leeches and certainly many more yet to be discovered.

In fact, it was long thought that this unique underground ecosystem was also inhabited by surface-dwelling species widespread in Europe. Convinced that this scenario is highly unlikely, scientists Dr Varpu Vahtera (University of Turku, Finland), Prof Pavel Stoev (National Museum of Natural History, Bulgaria) and Dr Nesrine Akkari (Museum of Natural History Vienna, Austria) decided to examine a curious centipede, collected by speleologists Serban Sarbu and Alexandra Maria Hillebrand, during their recent expedition to Movile.

“Our results confirmed our doubts and revealed that the Movile centipede is morphologically and genetically different, suggesting that it has been evolving from its closest surface-dwelling relative over the course of millions of years into an entirely new taxon that is better adapted to life in the never-ending darkness,” explain the researchers.

“The centipede we described is a venomous predator, by far the largest of the previously described animals from this cave. Thinking of its top rank in this subterranean system, we decided to name the species Cryptops speleorex, which can be translated to the “King of the cave”, they add.

The scientists exploring the Movile cave (Romania)
Photo by Mihai Baciu

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Original Source:

Vahtera V, Stoev P, Akkari N (2020) Five million years in the darkness: A new troglomorphic species of Cryptops Leach, 1814 (Chilopoda, Scolopendromorpha) from Movile Cave, Romania. ZooKeys 1004: 1-26. https://doi.org/10.3897/zookeys.1004.58537