Importance of Small Water Bodies for Diversity of Leeches (Hirudinea) of Western Balkan

Abstract

The Balkan Peninsula is known as a biodiversity hotspot. This area is characterized by diverse climate, orographic and hydrological conditions which represent a good basis for the diversity of flora and fauna. The fauna of leeches (Hirudinea) is no exception. The majority of European species are recorded in this area, many of which are endemic to the Balkans. Contemporary studies have described several species new to the science, and a few subspecies have been risen to the species level after detailed investigation (Croatobranchus maestrovi, Dina krasensis, D. dinarica, D. minuoculata, D. sketi, D. prokletijaca, Trocheta dalmatina, Glossiphonia balcanica). The area of Dinaric Alps (Karst) with its springs, streams and glacial lakes are home to almost all of these newly described species but also other common European species. These habitats are under various anthropogenic pressure, springs are driven in to pipes for irrigation or for human use, and on many small rivers mini hydro-power plants are being built which further endanger these fragile habitats and animal communities that inhabit them. The Mediterranean medicinal leech (H. verbana) was exported in large numbers through history form the area of Balkan Peninsula to Western Europe for medicinal use. Today, species of medicinal leeches are under numerous international and national protection acts and its trade and commercial use is very limited or prohibited. The main threat is the destruction and deterioration of suitable habitats, mainly wetland areas, marshes and ponds in the flood zones of rivers.