The molluscs and their habitats in Sashtinska Sredna Gora Mts. (Southern Bulgaria)

Abstract

The aim of this study was to investigate the mollusc species diversity of Sashtinska Sredna Gora Mts. (Southern Bulgaria) in detail, and to obtain some data on the distribution of the malacofauna both in habitats and in geographical areas of this mountain. The survey was carried out during the period of 20 Oct 2007 – 12 Nov 2008. Total 49 localities were examined, and their co-ordinates were given, 78 mollusc species were registered in the study area, from which 75 were new records for Sashtinska Sredna Gora Mts. Seventeen molluscan habitats were studied separately, from which the forests on river banks dominated by Salix sp. and Alnus glutinosa, open grassy terrains with short vegetation, and oak forests showed the highest species diversity. Considering the base rock type molluscan communities were separated in two main groups: a complex of species in the limestone areas, and another one inhabiting the volcanic/non limestone terrains. The artificial substrate even considered as a calcium source, in our area had played a little role on diversity. It held a species complex not so close related to the limestone faunas than with the volcanic base rock ones, on which it was situated.