The European land leech: biology and DNA-based taxonomy of a rare species that is threatened by climate warming

The European land leech Xerobdella lecomtei was discovered in 1868 and is one of the rarest animals on Earth. During the 1960s, several individuals of these approx. 40 mm long, cold-adapted terrestrial annelids that inhabit the moist soils of birch forests around Graz, Austria, were investigated. Only one original research paper has been published on the biology of this species. Between 2001 and 2005, we re-investigated the morphology of preserved specimens and searched for living individuals in their natural habitat that appeared to be intact. We found only one juvenile individual (length approx. 10 mm), indicating that this local leech population became largely extinct over the past four decades. The feeding behaviour of our ‘lonesome George of the annelids’ was studied and is described here in detail. After its death, the Xerobdella individual was used for chemical extraction and molecular studies (deoxyribonucleic acid [DNA] barcoding, based on one gene, the mitochondrial cytochrome c oxidase subunit I). In addition, novel DNA barcodes for a land leech from Madagascar and a recently discovered species from Europe were obtained. Our phylogenetic tree shows that X. lecomtei is not a member of the tropical land leeches (family Haemadipsidae), as previously thought, but represents a separate line of descent (family Xerobdellidae). The decline of the local leech population around Graz correlates with a rise in average summer temperatures of +3°C between 1961 and 2004. This warming led to a drastic reduction in the moisture content of the soil where X. lecomtei lives. We suggest that human-induced climate change without apparent habitat destruction can lead to the extinction of populations of cold-adapted species that have a low colonization ability.     

Comparative analysis of tolerance to pesticides in annelids

The tolerance of annelids (11 oligochaete and 13 leech species) to several organophosphate pesticides, polychloropinene, phenol, and copper sulfate was compared in an acute experiment. The dependence of pesticide resistance on specific biological and ecological features of the annelid species and their position in the phylogenetic series is discussed.     

Distribution of leeches in aquatic ecosystems of the city of Yekaterinburg and its vicinity

Ecological features and species composition of leeches were studied in 25 water bodies located in the city of Yekaterinburg and its vicinity. Specific features of their occurrence and distribution in water bodies of various types were analyzed. Dominant, mass, common, and rare species were distinguished.     

Species Diversity of Leeches Populating Water Bodies of the Middle Urals

Russian Journal of Ecology -