A multinational team of scientists headed by Dr Adrienne Jochum from the University of Bern, Switzerland, has described two new species of the genus Zospeum from the caves of the Basque Country and the province of Burgos.
Moist muddy layer with Zospeum vasconicum in the Cueva Arrikrutz, Gipuzkoa, Spain. Image credit: Jochum A et al.
Members of the genus Zospeum are blind snails with semi-transparent shells. They are amongst the smallest terrestrial gastropods known, with some species reaching 1 mm (0.04 inch) in shell size and living in caves at depths as deep as 950 meters (3,100 feet).
These snails inhabit moist, muddy cave walls, rock crevices, speleothems and ceilings in the deep recesses of karst caves, far from the entrance zone.
Their evolution dates back to the Cenozoic era, approximately 65 million years ago.
The two new Zospeum species are named Z. vasconicum and Z. zaldivarae.
Zospeum vasconicum is “named after the pre-Roman Era Vascones Tribe (from Latin gens Vasconum), which at the arrival of the Romans during the 1st century, inhabited a territory spanning the region between the upper course of the Ebro River and the southern basin of the western Pyrenees,” Dr Jochum and his colleagues from the University Bochum in Germany and the University of the Basque Country in Spain wrote in the paper, published in the journal ZooKeys.
“This tribe is considered (disputed) the ancestor of the Basque People.”
Zospeum vasconicum and Z. zaldivarae. Scale bar – 0.5 mm. Image credit: Jochum A et al.
“Shell approximately 1.2 mm, transparent, elongate or elongate-conical with an entire, roundish and more or less thickened peristome, lacking obvious apertural barriers, but often with an obsolete lamella (denticle) in the parieto-columellar corner,” the scientists wrote in the paper.
Four populations of Zospeum vasconicum are known to occur in Sierra de Aitzgorri and Sierra de Aramotz-Anboto massifs in the provinces of Gipuzkoa and Bizkaia, Spain.
Zospeum zaldivarae is only known from the Cueva de Las Paúles in the province of Burgos.
This species is named after Pilar Zaldivar, a biologist and speleologist from the Niphargus Speleological Team.
“Shell minute (1.5 mm), turbinate-conical, with approximately 5 ½ regularly coiled, convex, rounded whorls; shell transparent when fresh, chalky white with age, comparatively large, rather variable in shape.”
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Jochum A et al. 2015. Two new species of Zospeum Bourguignat, 1856 from the Basque-Cantabrian Mountains, Northern Spain (Eupulmonata, Ellobioidea, Carychiidae). ZooKeys 483: 81-96; doi: 10.3897/zookeys.483.9167
