The aims of this study were to identify the taxonomic diversity and abundance of psammonic ciliate communities in mesotrophic and eutrophic lakes (Łęczna-Włodawa Lakeland, eastern Poland). The effect of selected physical and chemical water parameters on ciliates community was also analysed. Psammon samples were collected during three seasons: spring, summer and autumn of 2010. In each lake, in the psammolittoral, samples were collected in the euarenal, higroarenal, and hydroarenal zones. A total of 53 ciliate taxa were recorded. The highest value of the Shannon-Weaver index was recorded in summer in eutrophic lake (2.79). At the same time in mesotrophic lake, a lower value of the index was determined (0.79). The mean numbers of ciliates ranged from 516 ind.cm-3 in the eutrophic lake to 191 ind. cm-3 in the mesotrophic lake. In eutrophic lake, the highest number of ciliates was recorded in the euarenal (649 ind. cm-3), and the lowest in the higroarenal (425 ind. cm-3). In the mesotrophic lake, the highest average numbers were determined in the higroarenal (235 ind. cm-3), and the lowest in the hydroarenal (155 ind. cm-3). Irrespective of the lake trophy, Hymenostomata (Paramecium sp., Glaucoma sp., Uronema nigricans) occurred in the highest numbers (from 13 to 95%). The results demonstrated that N-NH4, P-PO4 and TOC can strongly regulate the abundance and taxonomic composition of ciliates. The strongest correlations between numbers of ciliates and physical and chemical water parameters were observed in the higro- and hydroarenal zones of the eutrophic lake.
The checklist of Admiralty Bay polychaetes elaborated on the basis of historical and current data includes 120 benthic and 5 pelagic species. Admiralty Bay is the most intensively sampled area in the Antarctic, taking into account polychaete fauna, and the checklist of Polychaeta may be therefore considered as a rather comprehensive one. In the sublittoral soft bottom three dominant species: Leitoscoloplos kerguelensis, Tauberia gracilis and Ophelina syringopyge constitute almost 50% of all collected polychaetes (20%, 16% and 13% respectively). Rhodine intermedia, Tharyx cincinnatus, Aricidea (Acesta) strelzovi, Apistobranchus sp., Cirrophorus brevicirratus, Microspio moorei, Maldane sarsi antarctica, Aglaophamus ornatus and Asychis amphiglypta make up a group of species of considerable abundance (a further 30% of author's collection). The average abundance of polychaetes of the sublittoral soft bottom was estimated at 120 individuals per 0.1 m2, with the observed maximum 390 individuals per 0.1 m2.
Soft bottom fauna have been sampled along the Spitsbergen fjord depression entering shelf, slope and Greenland Sea Ocean Basin at 200, 300, 500, 1500, 2000 and 3000 m depths. From 19 samples covering 1.9 m2, 4295 individuals of 194 macrofauna species have been sorted. Density decreased markedly from over 6000 ind/m2 in shelf stations to some 600 ind/m2 below 1500 m depth. Only two taxa (Chaetozone group and Lumbrineris sp. A) occurred in more than 75% of samples, 55 taxa (28% of the total) were represented by single specimens only. The highest number of species per sample (65 taxa in 0.1 m2) was noted at 525 depth. There were 14 eurybathic species and the same number of taxa were found exclusively below 2000 m depth, while 117 species were found only shallower than 300 m depth.
In the years 2002–2004 strains of Bacillus thuringiensis and 37 species of entomopathogenic fungi were isolated and identified in the Polish and Belarussian parts of Białowieża Forest (BF). Mitosporic fungi and bacteria dominated in litter sperficial soil layer, forest, litter and floor vegetation whereas entomophtoralen fungi prevailed in bushy undergrowth layers and tree crowns. The dominant species Beauveria bassiana was observed in forest floor, subcortical habitats on dead trees, meadows and rushes. The species Entomophthora israelensis, Beauveria cf. bassiana, Paecilomyces suffultus and P. tenuipes were for the first time described as insect pathogens in BF. Entomophthorales seem to hold much greater part than mitosporic forms in the whole diversity of entomopathogenic fungi. Relatively rich sets of these fungi recognised in BF during last decades confirm the predestination of this area as highly significant refuge for other groups of arthropod pathogens, and it should encourage scientists to widen their research and contribute to a rather scarce knowledge in this field.
Morphological description of seeds is a required step for analysis of biodiversity in natural populations and may give clues to adaptive strategies in species evolution. A cardioid is the curve described by a point of one circumference rolling around another circumference of equal radius. Models based on adjustment of seed shape with cardioid curves have been described for Arabidopsis thaliana and the model legumes Lotus japonicus and Medicago truncatula. In this work the model is applied to analyze seed morphology in populations of two subspecies of Capparis spinosa growing in Tunisia. Adjustment of seed images to cardioid curves, followed by statistical analysis of similarity in the complete images as well as in each of four quadrants, allows an accurate description of seed shape. The results show differences in morphology between subspecies. Seeds of subsp. rupestris present higher diversity of shape than seeds of subsp. spinosa. This may indicate primitiveness of C. subsp. rupestris seeds, associated with nonspecialization. The results are discussed in relation to the ecological strategies of both subspecies in their evolution.
The presented paper reports data from malacological and pedological studies carried out at sites representing diverse biotopes (beech wood, coniferous forest, and meadow) located 2 km away from the Dyckerhoff Cement Plant in Sitkówka-Nowiny in 1992 and in 2008–2009. The studies aimed to determine physicochemical properties of soils exposed to cement and limestone dust emission and to identify composition of snail communities inhabiting three different biotopes in relation to physicochemical properties of soils, and to grasp the dynamics of the alkalization-dependent changes in physicochemical properties of soils and their impact on the composition and ecological structure of malacofauna.