New and interesting diatom species (Bacillariophyceae) from Swedish rivers

During a morphological and taxonomical survey of the diatom flora of Swedish rivers, five new species have been observed: Caloneis langebertalotii Van de Vijver, Ector & Jarlman sp. nov., C. minuscula Van de Vijver, Ector & Jarlman sp. nov., Fragilaria sandellii Van de Vijver & Jarlman sp. nov., Geissleria scaniae Van de Vijver, Ector & Jarlman sp. nov. and Hippodonta olofjarlmanii Van de Vijver & Jarlman sp. nov. Based on detailed light and scanning electron microscopical analysis, it is clear that these five species represent new taxa that can distinctly be separated from other similar taxa. A sixth species, Gomphosphenia stoermeri Kociolek & E. W. Thomas in Thomas et al., recently described from the United States, was found in several rivers in northern Sweden. The paper presents all morphological details for the six species, shows information on their distribution and ecology and discusses their taxonomic position and characteristic features.