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EN
The aim of the study was to compare the physical-chemical quality parameters of shallow groundwater quality in peat bogs of the Łęczna-Włodawa Lake District in the context of the occurrence of selected boreal species of plant relics: dwarf birch (Betula humilis Schrank), downy willow (Salix lapponum L.) and swamp willow (Salix myrtylloides L.). Analyzes of shallow groundwater quality parameters included physical-chemical parameters: reaction (pH), electrolytic conductivity (EC), dissolved organic carbon (DOC), total nitrogen (TN), ammonium nitrogen (NH4), nitrite nitrogen (NO2), nitrate nitrogen (NO3), total phosphorus (TP), phosphate (PO4), sulfate (SO2), sodium (Na), potassium (K), calcium (Ca) and magnesium (Mg) by certified laboratory tests. It was found that the natural hydrochemical specification of peat bogs is characterized by fluctuations associated with the dynamics of internal metabolism of peat ecosystems without the visible impact of anthropopressure. This is confirmed by the concentration of nutrients: TN at the study sites were within a broad range of mean values: 16.92–45.31 mg·dm–3; NH4 (0.55–0.76 mg·dm–3); NO2 (0.06–4.33 mg·dm–3); and NO3 did not exceed 0.2 mg·dm–3, and concentration of TP adopted mean values in a range of 0.22–0.42 mg·dm–3. The studied physical-chemical factors of shallow groundwater were within the habitat preferences of the studied species, but in differentiated qualitative and quantitative ways determined optimal conditions for building the population of the studied species. Particularly values of TP lower than other obtained values in a range of: 0.08–0.32 mg·dm–3; PO4 = 0.1 mg·dm–3; TN = 2.2–21.2 mg·dm–3; NH4 = 0.1–0.46 mg·dm–3; DOC = 24.6–55.9 mg·dm–3, as well as higher than average pH values in a range of: 5.34–5.95 and concentration of Ca = 5.67–28.1 mg·dm–3 and Mg = 0.56–2.41 mg·dm–3, as well as EC = 72.1–142.3 μS·cm–1 can be treated as a condition favouring proper development of the population of dwarf birch. For Salix lapponum: a reduced level of values of nitrogen fractions (TN = 3.01–18.84 mg·dm–3; NH4 = 0.1–0.41 mg·dm–3), a reduced level of values of phosphorus fractions (TP = 0.09–0.44 mg·dm–3; PO4 = 0.1–0.44 mg·dm–3), part of ions (Ca = 4.39–19.63 mg·dm–3; Mg = 0.77–3.37 mg·dm–3), pH = 5.9–6.4, EC = 124–266 μS·cm–1 and DOC = 24.1–57.5 mg·dm–3. For the equally studied Salix myrtylloides, such conditions were met by: TP = 0.1–0.41 mg·dm–3; PO4 = 0.1–0.18 mg·dm–3, DOC = 27.5–50.9 mg·dm–3, pH = 5.3–5.94 and EC = 62.2–139.3 μS·cm–1.
EN
Over 700 specimens of Corynosoma strumosum (Rudolphi, 1802) Lühe, 1904 were collected from one young male Caspian seal, Pusa caspica (Gmelin) in the southern land-locked Caspian Sea in April, 2009. Collected worms showed consistent variations from those reported by other observers using light microscopy especially in proboscis hook and trunk spine patterns. SEM images revealed many features that have not been previously reported including the shape and distribution of trunk spines, dorsoventral differences in proboscis hooks and their organization, the baldness of anterior proboscis, the rough egg topography, epidermal micropores, and variations in the female gonopore. This isolated population of C. strumosum from the land-locked Caspian Sea is distinguished from others reported from open waters elsewhere by the distribution of trunk spines, consistently smaller size of trunk and testes, larger eggs, and fewer proboscis hooks. Histopathological sections reveal the invasive path of worms in host tissue with damage to intestinal villi and worm encapsulation. Information obtained from SEM studies and histopathological sections is reported for the first time.
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