Diversity and a biogeographical review of the earthworms (Oligochaeta: Lumbricidae) of the Balkan Mountains (Stara Planina Mountains) in Serbia and Bulgaria

Abstract

In this paper we summarize the knowledge on earthworm diversity in the Balkan Mountains (Stara Planina Mountains) based on new findings and published data in order to establish the first list of known earthworm taxa from the entire area of the Balkan Mountains. During investigations in the western part of the Balkan Mountains (western Stara Planina Mountains), 24 earthworm species were recorded altogether. Among them, 10 taxa represented the first findings for the whole territory of the Balkan Mountains (Allolobophora robusta spasenijakaramani, Aporrectodea smaragdina, Dendrobaena byblica, Dendrobaena hortensis, Dendrobaena illyrica, Dendrobaena jastrebensis, Dendrobaena vejdovskyi, Dendrobaena veneta, Helodrilus balcanicus balcanicus, and Helodrilus cernosvitovianus). The complete list of lumbricids from the Balkan Mountains contains 40 taxa belonging to 14 genera. With respect to the zoogeographic situation, the majority of them belong to peregrine, endemic, and trans-Aegean species. Our data show that the degree of endemism for the whole Stara Planina Mountains is relatively high (20%). Summing up the 9 endemics and the Balkanic (Moesian and Illyric) species, 27.5% of the total lumbricid fauna shows an autochthonous character. The impressive earthworm diversity shows that the Balkan Mountains are a territory of considerable species richness.