Faunistic patterns and diversity components of leech assemblages in karst springs of Montenegro

The aim of this study was to reveal faunistic and diversity patterns and to assess the effects of environmental factors on the differentiation of leech communities. This study covers investigations of 82 karst springs in Montenegro from 2009-2017. The communities were analyzed in respect to five wellspring types - caves, sublacustrine, limnocrene, rheo-limnocrene and rheocrene. The percentage of substrate types and aquatic vegetation cover was recorded alongside water parameters. In total, 18 leech species were identified, of which two were recently described as new species for science (Dina minuoculata Grosser, Moritz and Pesic, 2007 and Glossiphonia balcanica Grosser and Pesic, 2016). K-means clustering was used to classify leech assemblages into three homogenous groups. The patterns of leech communities and the components of both alpha and beta diversity were examined in identified groups of assemblages. The significance of environmental factors and the impact of selected factors were assessed through forward selection analysis, CCA and RDA. Our results indicate that the type of spring and the environmental variables, as well as the combination of biotic and abiotic factors in a microhabitat dictate the distribution of leeches.