Joanna Czerwik-Marcinkowska

Differences in the ultrastructure of two selected taxa of phytoplankton in a thermally stratified Lake Holzmaar (Germany)

Abstract This paper presents the results of ultrastructural studies and ecological aspects of some phytoplankton species belonging to the groups of cyanobacteria (Planktothrix rubescens, Synechocystis aquatilis) and green algae (Desmodesmus grahneisii). Specimens were collected during summertime from the mesotrophic and stratified Lake Holzmaar (Western Germany) as planktonic forms from the pelagic zone. The highest cyanobacterium concentration was detected in the metalimnion, where the alkaline pH, low phosphorus and high nitrogen contents were recorded. P. rubescens was characterized by straight filaments up to 1000 μm long and 5.4-8 μm wide and numerous aerotopes in cells. The accompanying algae were identified by ultrastructural analysis and photographic documentation was provided. In the case of D. grahneisii, chloroplast was situated in the parietal part of cell, with one large, oval pyrenoid and, in addition, the granular and spiny cell wall was an important taxonomical criterium for the Desmodesmus genus. This is in contrast with the cyanobacterium S. aquatilis, in which a homogeneous content with visible chromatoplasma was mostly distributed throughout the cell. This algal association was stable in the epilimnion characterized by the presence of high temperature, pH values (>8), nitrate nitrogen and oxygen concentrations

Biodiversity of Limestone Caves: Aggregations of Aerophytic Algae and Cyanobacteria in Relation to Site Factors

ABSTRACT The most numerous limestone caves are in the smallest national park in Poland (the Ojców National Park). A total of 50 algal samples were collected from ten caves, each having different environmental factors such as light intensity, temperature and humidity. The morphological and ecological variability of cyanobacteria and algae were studied using fresh samples, cultures grown on agar plates, and documented with TEM, SEM and LM. Light microscopic observations showed that aerophytic cyanobacteria were the most important component of the cave′s photosynthetic microflora. Among cyanobacteria, the following genera were frequently encountered: Aphanocapsa, Chroococcus, Gloeocapsa, Leptolyngbya, and Synechocystis. Whereas the green algal genera, Apatococcus and Klebsormidium, often occurred with Chlorella, Muriella, Neocystis and the diatoms, Orthoseira and Pinnularia. Most of the algal species appeared to be cosmopolitan, ubiquitous, had simple nutrition requirements and wide ecological tolerance (they reproduced rapidly and were easily adaptable to new conditions). The cave′s microhabitats offered relatively stable microclimatic conditions and they seemed to be responsible for the observed distribution of aerophytic algae and cyanobacteria. The Shannon-Wiener index (H′) ranged between 4.9 and 3.9, and the Kruskal-Wallis test showed that these differences were statistically significant.

Ulva flexuosa subsp. pilifera (Chlorophyta, Ulvophyceae) from the Wielkopolska region (West Poland): a new observation on the ultrastructure of vegetative cells

Ulva flexuosa subsp. pilifera previously known from northern Poland, from the channel near Szczecin and ponds near Łódź, has recently been found in the Malta Reservoir in the Wielkopolska (West Poland) region. Specimens collected in the Wielkopolska region were examined in detail, also under a transmission electron microscope (TEM). The morphometric analysis of Ulva thalli (both young and mature specimens) was performed in order to study the differences in the ultrastructure of vegetative cells. Rectangular cells in young thalli measured from 32.21–55.81 μm to 20.24–35.12 μm, and they formed clear longitudinal rows, while cells in the mature specimens ranged from 25.09–47.66 μm to 18.90–31.56 μm. This study indicates that vegetative cells of the mature thalli show tendency towards distortions of both the longitudinal and transverse cells arrangement. This distortion is determined by the development of possible carbonate calcium crystals on the thalli surface. The ultrastructural analysis (TEM) confirmed that the structure and placement of thylakoids is genus/species specific.

Diatom species diversity and their ecological patterns on different substrates in two karstic streams in the Slovak karst

Many karstic streams are threatened both by anthropogenic and climate changes, but little is known about their algal biodiversity and conservation value, especially in the Slovak Karst. Diatom assemblages occurring on seven substrates, including stones, mud, submerged mosses and filamentous algae: Cladophora glomerata, Vaucheria sp., Ulothrix zonata, Spirogyra sp. in two nameless karstic streams in the Krásnohorská Dlhá Lúka Village and the Gombasek Cottage Settlement (the Slavec Village) in the Košice Region of central-eastern Slovakia (the Silická Plateau) were studied. A total of 124 diatom taxa were found at four sites, where epilithic and epiphytic diatom assemblages dominated. Both species’ richness and Shannon-Wiener indices showed congruent biotic integrity. The dominant taxa were alkaliphilous, halophobous-oligohalobous, requiring xeno-oligosaprobic and oligotrophic waters. Diatoms include: Diploneis krammeri, Encyonema ventricosum, Gomphonema acuminatum, Gyrosigma attenuatum, Navicula tripunctata, and Paraplaconeis cracoviensis. The latter species is a new report for Slovakia, reflecting the calcareous, geological nature of the Silická Plateau (the Slovak Karst). Diatom assemblages in two karstic streams consisted mainly of small-celled species of Achnanthidium, Amphora, Caloneis, Planothidium, and Stauroneis. Our results showed that the diatom assemblages were mostly structured by environmental factors of calcium and pH gradients, confirmed by canonical variates analysis (CVA) and Monte Carlo permutation tests. However, unique spatial and biological gradients, specific to different guilds related to each other, were also evident. The Slovak karstic streams should be especially protected and regularly monitored.

Relationships between diatoms and environmental variables in industrial water biotopes of Trzuskawica S.A. (Poland)

Abstract The heterogeneous nature and widespread anthropogenic impacts on industrial water biotopes in the Trzuskawica S.A., pose challenges to biomonitoring of this habitat. Generally, the concentration of trace elements in the industrial water biotopes reflects the anthropogenic impacts. With X-ray fluorescence method (TXRF) in waters 17 elements:P,S,Cl,K,Ca,Ti,Cr, Mn,Fe,Ni,Cu,Zn,Br,Rb, Sr, Ba, Pb were revealed. High amounts of Ca, from 300 ppm to 198 ppm in May and from 999 ppm to 231 ppm in September 2015, was determined. A total of 36 diatoms were found in two reservoirs and drainage ditch, but only three taxa: Cymatopleura radiosa, Navicula upsaliensis and Nitzschia angustata were present in all 7 sampling sites. These species are known to be tolerant to organic pollution, eutrophication, and also characteristic for limestone waters. The results of CVA showed that dintoms in the water reservoir stocked with fish were distinguished by highest species richness. The relationships between diatoms and environmental variables confirm the positive correlation with the currently functioning industrial plant (despite the increased water temperature and large content of trace elements). Our results suggest that, though heterogeneity in both diatoms and selected elements in industrial waters, diatoms can be useful indicators of habitat conditions.