Phototrophic microflora of dystrophic Lake Sęczek, Masuria, Poland

Abstract

Microflora of cyanobacteria and algae of small forest dystrophic Lake Sęczek located in the Masurian Lake District, NE Poland, was investigated in 2012 and 2013. A total of 16 genera with 7 species of cyanobacteria and 56 genera with 74 species, 6 varietas and forms of algae were determined. Most of them represented commonly occurring microorganisms of slightly acidic waters, but some of them are considered rare, i.e. the oscillatorian cyanobacterium Katagnymene accurata Geitler (for the first time found in Poland), and green algae Coenochloris sphagnicola Hindák, Mucidosphaerium sphagnale (Hindák) C. Bock, Pröschold et Krienitz, Closterium navicula (Bréb.) Lütkem., and Cosmarium cf. aphaerosporum var. corribense (W. et G.S. West) Krieger et Gerloff., which are described in more detail. As regards the species diversity, the plankton of the lake was rather species-poor in contrast to the algal communities in the Sphagnum littoral.

Geometric Morphometrics of Bilateral Asymmetry in Eunotia bilunaris (Eunotiales, Bacillariophyceae) as a Tool for the Quantitative Assessment of Teratogenic Deviations in Frustule Shapes

“…The valves of E. bilunaris are typical for arcuate isopolar outlines with rounded polar ends that are slightly tapered (Figure 1). Interestingly, in the specimens of this species, teratogenic deformations of valvar outlines have been repeatedly reported [3,6,7,9,10,13]. These deformities were largely linked to adverse environmental conditions, such as heavy metal pollution [6,7] or low pH [9,10].…”

“…Interestingly, in the specimens of this species, teratogenic deformations of valvar outlines have been repeatedly reported [3,6,7,9,10,13]. These deformities were largely linked to adverse environmental conditions, such as heavy metal pollution [6,7] or low pH [9,10]. Our study was based on the analysis of cells from a natural population of E. bilunaris with a relatively high proportion of visibly deformed cells.…”

“…Diatoms are generally sensitive to the environmental conditions of their habitats, which is reflected in the changes of their species composition in natural communities and in the patterns of morphological variation of frustules [4,5]. Teratogenic changes in frustule morphology have been well documented in scientific literature, especially in relation to various stress factors, such as increased sublethal concentrations of heavy metals [6][7][8], acidification [9,10], increased radiocativity [11], and organic pollution [12]. These teratogenic changes affect different parts of frustules, but the most common are deformities of the frustule outlines compared to their species-specific symmetric shapes.…”

“…In contrast, the symmetry across the transapical axis of eunotioid valves is typically preserved, and two cellular halves cannot be distinguished from each other among different individuals. Members of the genus Eunotia Ehrenberg, the most frequently distributed genus of this lineage, occur in a wide variety of habitats, including the freshwater phytobenthos and subaerial biofilms and soils [2,[9][10][11]28]. In this study, the eunotioid diatom morphotype was selected to explore the potential of geometric morphometric analysis of asymmetry in assessing the severity of teratogenic deformities.…”

Looking back, looking forward: a review of the new literature on diatom teratological forms (2010–2020)

“…Low pH levels were recognized as the single possible cause of teratological form development in a study conducted at vent sits in the Aeolic Islands (Rogelja et al, 2016), as well as in a small dystrophic lake in Poland (Grabowska et al, 2014). In a recent past, diatom teratological forms have also been used for identifying and tracking those areas affected by acid precipitations, such as the Great Smoky Mountains National Park (USA) (Furey et al, 2009).…”