Cyanobacteria of the thermal spring at Pancharevo, Sofia, Bulgaria

Eight taxa of cyanobacteria were identified in the thermal spring at Pancharevo (in the Sofia basin, Bulgaria). As well as the widespread Lyngbya thermalis, Phormidesmis molle (syn. Phormidium molle), Phormidium papyraceum, Phormidium corium and Mastigocladus laminosus, four species were identified for the first time in Bulgaria: Calothrix thermalis, Gloeocapsa gelatinosa, Leibleinia epiphytica and Symploca thermalis

Centric diatoms of large rivers and tributaries in Hungary: morphology and biogeographic distribution

Centric diatoms of 107 different Hungarian running waters were investigated. Among them the largest was the River Danube, from which more than one hundred plankton samples were analysed by scanning electron microscopy (SEM). Only one sample was analysed from creeks, which were the smallest running waters analysed in this study. There were also channels with slow currents flowing out of rivers or connecting different rivers.In total, 41 centric taxa belonging to 11 genera were found during this study. The average number of taxa found in a single watercourse was 7, the maximum 40 and the minimum 1. Cyclotella meneghiniana was the most frequently encountered species (present in 60% ofsites). Twelve taxa were found in more than 20% of sites, 7 taxa between 5–10% and 6 taxa only in one site

sp. nov. : morphological and ecological characters of a new cyanophyte/cyanobacterial species from Lake Bled, Slovenia

The morphology and ecology of a†new species of the cyanophyte/cyanobacterial genus Aphanizomenon Morren ex Bornet et Flahault, A. slovenicum Rekar et Hindák, are described from Lake Bled, NW Slovenia. The species produced a heavy water bloom in May - December 1997 but disappeared during 1998. Macroscopic flakes of bundles of trichomes similar to A. flos-aquae (L.) Ralfs ex Bornet et Flahault formed in a layer between 10 - 20 m depth. They differed from A. flos-aquae by shorter and narrow short cylindrical to barrel-shaped cells, and by trichomes that sometimes consisted of morphologically different cell sections. Maximum abundance was found in August : 655 trichomes.m1-1. Heterocytes were occasionally present and akinetes have been observed only in laboratory cultures. The main characteristics of the investigated cultures of A. slovenicum and A. flos-aquae isolated from a fishpond at Ledava (NE Slovenia) are given