Fottea, 2015 (vol. 15), issue 2

Community structure of corticolous microalgae within a single forest stand: evaluating the effects of bark surface pH and tree species

Anna Štifterová, Jiří Neustupa*

Fottea 2015, 15(2):113-122 | 10.5507/fot.2015.013  

Community structure of corticolous macro-epiphytes, such as lichens and mosses, usually strongly correlates with bark characteristics related to the taxonomic identity of the host tree. However, the reasons for the occurrence of similar patterns of microalgal corticolous biofilms are unclear and have rarely been investigated. In this study, we surveyed aerial phototrophic biofilms growing on the bark of Acer, Alnus, Fagus, Fraxinus and Picea trees in a single stand of a temperate forest. A flathead electrode was used to measure and evaluate the effect of bark surface pH on microalgal species richness and composition....

Diatom assemblages of non-living substrates in petrifying Cratoneurion springs from lower Belgium

Luc Denys, Patrik Oosterlynck

Fottea 2015, 15(2):123-138 | 10.5507/fot.2015.014  

Diatom assemblages were examined from non-living substrates in thirteen springs supporting the Natura 2000 habitat type 'Petryfing springs with tufa formation' in the southern part of Flanders. More than 300 taxa were recorded, including some which appear to be particularly associated with this kind of environment. Even though a number of characteristic taxa and diatoms characterizing fast-flowing springs of more elevated terrain remained absent, local species richness was higher than reported from carbonate springs elsewhere in Europe. Relative abundance of 'Red List' taxa was, however, substantially lower. Taxon richness was not related to measured...

Cocconeis Ehrenberg taxa (Bacillariophyta) with a marginal row of simple processes: relationship with the valvocopula system and distinctive features of related taxa

Catherine Riaux-Gobin, Andrzej Witkowski, Pierre Compère, Oscar E. Romero

Fottea 2015, 15(2):139-154 | 10.5507/fot.2015.015  

As first observed on a group of taxa related to Cocconeis peltoides Hustedt, several other Cocconeis Ehrenberg (Bacillariophyta) taxa possess a row of minute marginal pores on the external side of their sternum valve (SV) connected to small and simple internal portules, or processes. These processes are often located in continuity with the striae, but can also be slightly shifted or distant from the distal areola of the striae. The row of pores is often, but not always, externally separated from the stria by a crista marginalis. Within Cocconeis, and possibly all raphid diatoms, these processes seem unique and restricted to a few...

Two new species of Mastogloia Thwaites ex W. Smith (Bacillariophyceae) from Sawa Lake, southern Iraq

Adil Y. Al-Handal, Chiara Pennesi, Dawood S. Abdullah

Fottea 2015, 15(2):155-164 | 10.5507/fot.2015.016  

Two new species of the genus Mastogloia are described. Mastogloia sawensis sp. nov. and M. vestigiostriata sp. nov. were encountered as epiphytes on Chara sp. which covers the sediment of Sawa Lake, an isolated saline water body in southern Iraq. Mastogloia sawensis belongs to the section Lanceolatae and is closely similar to M. lanceolata but differs in raphe curvature, areolae shape and arrangement, and the presence of rounded pores at the junction of the partecta. Mastogloia vestigiostriata resembles under light microscopy to M. lyra and M. braunii but shows differences in several features...

Pediastrum Meyen sensu lato (Chlorophyceae) in the phytoplankton of lowland and upland water bodies of Central Europe (Poland)

Joanna Lenarczyk

Fottea 2015, 15(2):165-177 | 10.5507/fot.2015.017  

Thirteen species and thirteen varieties of microscopic green algae from the genus Pediastrum were found in thirty one localities scattered in lowland and upland water bodies in Poland. Seven groups of localities are distinguished with cluster analysis. The groups differ from each other in terms of Pediastrum communities and environmental variables (pH, conductivity, carbonate hardness, nitrate and orthophosphate concentrations). The most distinct group contains five coastal lakes, which have high pH values and chloride concentration. Because the lakes have a high number of taxa, including a few rarely occurring worldwide, they are considered...

Surirella prespanensis sp. nov. and Surirella hinziae sp. nov., two new diatom (Bacillariophyceae) species from ancient Lake Prespa (Macedonia/Albania/Greece)

Aleksandra Cvetkoska, Paul B. Hamilton, Zlatko Levkov

Fottea 2015, 15(2):179-189 | 10.5507/fot.2015.018  

Surirella is a polyphyletic and highly diverse diatom genus with more than 500 species described worldwide. Within a study of its diversity and distribution in the Republic of Macedonia, ancient Lake Prespa has been investigated, as "sister" to Lake Ohrid and part of a unique lake system with extraordinary age, biodiversity and number of endemic species. During the study, two new Surirella species have been identified and their LM and SEM based formal descriptions and differential diagnoses are provided herein. Surirella prespanensis sp. nov. has been observed in the contemporary and the fossil diatom flora of the lake. It can...

A detailed morphological, phylogenetic and ecophysiological analysis of four benthic Anabaena (Nostocales, Cyanobacteria) strains confirms deep heterogeneity within the genus

Andreja Kust, Eliška Kozlíková-Zapomělová, Jan Mareš, Klára Řeháková

Fottea 2015, 15(2):191-202 | 10.5507/fot.2015.019  

Four benthic Anabaena strains isolated from different localities in the Czech Republic were examined from the morphological, phylogenetic, and physiological points of view. The results of combined analysis showed distinct morphological dissimilarity between the studied strains, which were further found to belong to different phylogenetic groups based on the 16S rRNA gene phylogeny. To assess the temperature and light (irradiance) optima of the strains, we exposed them to various combinations of these two parameters. The experiment revealed unexpectedly high temperature and light optima for some of the strains, while others showed optima that...

Morphology, typification and critical analysis of some ecologically important small naviculoid species (Bacillariophyta)

Carlos E. Wetzel, Luc Ector, Bart Van de Vijver, Pierre Compère, David G. Mann

Fottea 2015, 15(2):203-234 | 10.5507/fot.2015.020  

The identity and nomenclatural history of several small-celled naviculoid taxa are revisited. The species discussed here are important from the ecological point of view since they are often dominant in benthic freshwater communities. The original concepts of several species that have suffered major taxonomic drift due to their entangled nomenclatural history are discussed, and forgotten epithets are resurrected. We examined the original material of Navicula aggerica E. Reichardt, Navicula atomoides Grunow, N. crassulexigua E. Reichardt, N. minima Grunow, N. minima var. typica R. Ross, N. minutissima (Kütz.)...

Cyclotella hinziae sp. nov. - a small Cyclotella (Bacillariophyceae) from subalpine lake Schliersee (Bavaria, Germany)

Václav Houk, Claudia König, Rolf Klee

Fottea 2015, 15(2):235-243 | 10.5507/fot.2015.021  

A small Cyclotella species (Thalassiosiraceae) from a subalpine lake Schliersee (Bavaria, Germany) is described. The species has characteristic valve morphology different from this of the other similar taxa. It differs from them especially with the presence of radially arranged ghost structures in the valve central part and with the presence and low number of transversal trabeculae inside the alveolus - maximally 6 in 1 μm. The valve morphology and ultrastructure of this taxon is described and its new name, Cyclotella hinziae, is proposed. Its valve morphology is compared and discussed with this of other similar taxa.

Algal communities of Kenyan soda lakes with a special focus on Arthrospira fusiformis

Michael Schagerl, Alfred Burian, Martin Gruber-Dorninger, Steve O. Oduor, Mary N. Kaggwa

Fottea 2015, 15(2):245-257 | 10.5507/fot.2015.012  

Soda lakes are simple in biodiversity, but due to their highly stochastic environmental dynamics unexpected shifts in species composition do occur. We studied key drivers for structuring phytoplankton communities and identified variables significantly influencing changes of Arthrospira fusiformis abundance in the Kenyan soda lakes, Nakuru and Bogoria. In both lakes, Arthrospira fusiformis dominated algal biomass, but in Nakuru, crashes of this taxon were recorded. The three variables sodium, pH and dry mass significantly contributed to the phytoplankton taxa pattern. Arthrospira was absent at highest turbidity and salinity levels,...

Epiphytic diatoms in lotic and lentic waters - diversity and representation of species complexes

Jan Kollár, Markéta Fránková, Petr Hašler, Markéta Letáková, Aloisie Poulíčková

Fottea 2015, 15(2):259-271 | 10.5507/fot.2015.022  

Small streams and shallow ponds represent sensitive ecosystems and attached diatoms can serve as integrative indicator with fast response to environmental changes. Development of methods for ecological monitoring throughout Europe and their calibration for particular ecoregions are not finished yet and databases need to be filled by data from undersampled regions and overlooked substrates. The present study aims to explore the diversity of epiphytic diatoms in unexplored catchment areas with special attention to substrate specificity and distribution of unresolved diatom species complexes. Significant differences were found in diversity of both regions...