Significance of the Apuseni Mountains (the Carpathians) in the origin and distribution of Central European earthworm fauna

Abstract

The earthworm fauna of the Apuseni Mountains is very rich in species, most of them are narrowly distributed endemics. Till now 37 Lumbricidae taxa are known from the Apuseni Mts. of which 13 occur exclusively here. This high number of local endemism is in accordance with the tectonic history of the region. In the southern part, with patchily distributed limestone areas, an accelerated insular-like speciation resulted in presence of many endemic large-bodied Octodrilus species. In the northern volcanic region other endemics such as Dendrobaena sp. nov. and Allolobophora prosselodacica were found. These species show an allopatric distribution with their Carpathian vicariant sister species D. attemsi and A. sturanyi dacidoides respectively. The origin of such Apuseni–Carpathian species pairs is possibly due to the Parathethys transgressions which repeatedly isolated the Carpathians from the Apuseni Mts. in the Tertiary period for a long time. After the final retreat of the Parathetys from the Carpathian Basin some species with larger dispersion capabilities such as Dendrobaena clujensis, Allolobophora sturanyi dacica, Allolobophora mehadiensis etc. migrated to lower altitude hilly and plain habitats forming the so called Dacian faunal element in Central Europe. Our molecular phylogenetic investigations (16S and COI sequences) corroborate this scenario. The high number of endemic species, as well as their distribution patterns places the Apuseni Mts. as a hot-spot of lumbricid earthworms’ diversification and distribution in Central Europe.

Key words:

• Earthworms
• Apuseni Mts
• the Carpathians
• evolution
• rDNA
• endemisms