Diversity and dynamics of the fungal community in Lake Ohrid

Abstract

Fungi are universally present in freshwater systems and are of great significance in the structural and functional organization of these ecosystems. The aim of this study was to assess the diversity of fungal communities in the ancient, oligotrophic Lake Ohrid and to investigate their spa- tial and temporal dynamics. The fungal community in Lake Ohrid consists of 36 species identified from 213 isolates. The autochthonous community is made up of 10 species belonging to the orders Saprolegniales and Peronosporales: Achlya americana, A. racemosa, Aphanomyces leavis, Dic- tyuchus monosporus, D. sterile, Pythium ultimum, Saprolegnia ferax, S. hypogina, S. monoica, and Saprolegnia sp. The allochthonous community is composed of 26 species from 15 genera of fungi. The dominant genera are Aspergillus (5 species, 13.86% of determined species), Penicillium (6 species, 16.66%), and Cladosporium and Fusarium (3 species, 8.33%). The species Kloeckera apiculata, Didiostible sp., Gliocladium roseum, and Varicosporium delicatum are identified here for the first time in freshwater ecosystems of the Balkans. Quantitative analysis of the fungal community showed that the number of propagules varied in the range of 0 to 19.5 × 10 3 l -1 . The diversity and abundance of both the autochthonous and the allochthonous fungal communities are greater in the littoral than in the pelagial zone. Our results represent the first hydromycological data for Lake Ohrid the region of Macedonia.