Symposium: Patterns of Subterranean Biogeography and Biodiversity
Disjunct distribution of terrestrial troglobiotic species in Europe: the case of Collembola.
Lukić, Marko*1,2,3; Delić, Teo3; Zagmajster, Maja3; Bedos, Anne4; Deharveng, Louis4
1Ruđer Bošković Institute, Zagreb, Croatia
2Croatian Biospeleological Society, Zagreb, Croatia
3Department of Biology, Biotechnical Faculty, University of Ljubljana, Ljubljana, Slovenia
4Muséum National d’Histoire Naturelle, UMR7205 CNRS/MNHN, Paris, France
Most species rich cave-dwelling groups in Europe share a similar pattern of distribution. At continental scale, a ridge of highest subterranean biodiversity was recognized at mid-latitudes, where a few hotspots containing numerous troglomorphic species can be found. These subterranean species mostly have narrow distributional ranges, limited to individual karst areas, often known even from a single cave. Yet, there are few taxa where disjunct geographical distributions in remote karst areas were documented. While such patterns have been studied and evaluated in some stygobionts, there are very few studies focused on terrestrial taxa. The latter present a challenge in understanding such patterns, having limited dispersal abilities when compared to many aquatic counterparts. We present three cases of disjunct distribution ranges among subterranean collembolan genera which match also those of a few other terrestrial arthropods. Genera Tritomurus (Tomoceridae), Ongulonychiurus (Onychiuridae) and subgenus Heteromurus (Verhoeffiella) (Entomobryidae) have highly troglomorphic species recorded in Dinaric and northern Pyreneo-Iberian karst regions, within hotspots of the European subterranean biodiversity ridge, more than 1000 km apart. These cases of disjunct geographical distributions are defined mostly on the basis of comparative morphological descriptions of the genera and species. We discuss the pattern in the light of new molecular studies conducted on Heteromurus (Verhoeffiella) which revealed some indications of polyphyly. Special attention shall be given to the striking morphological convergences of species living in remote karst areas.