Differences in the effectiveness of reproduction among ten breeding strains of the common carp Cyprinus carpio L. after stimulation of ovulation with carp pituitary homogenate or [(D‐Ala6, Pro9NEt) mGnRH‐a + metoclopramide] (Ovopel)

This study focused on the reproduction effectiveness of 10 breeding strains of common carp (Polish strains 2, 3, 6; Hungarian strains 0, W, 7; Lithuanian strain B; French strain F; Israeli strain D and Yugoslavian strain J) after stimulation of ovulation with carp pituitary homogenate or Ovopel. The percentage of females with recorded ovulation became higher after Ovopel treatment in as many as eight breeding strains (2, 3, 6, 0, W, B, F, D). The interaction between the spawning agent and the breeding strain was statistically significant (P ≤ 0.05) for the mass of spawn and non‐significant for traits determining the quality of eggs. Among the 10 breeding strains, in 4 (3, 7, B, J) the least‐squares means (LSM) for the weight of egg (g) were higher for fish stimulated with Ovopel. Among the strains tested, in seven (3, W, F, J, 2, 7, B), the LSM for the percentage of living embryos after 36 h incubation were higher for fish treated with Ovopel. The evaluation of reproduction effects based on the values of such parameters as the percentage of ovulating females, weight of eggs (g) and the percentage of live embryos (36 h) showed that after Ovopel treatment the poorer effects were obtained only for strains 6, 0 and D.     

Loss in macronutrient pools in bilberry and lingonberry in mesic Scots pine forests after Northern red oak introduction

Forest transformation from coniferous monocultures to mixed stands is being promoted worldwide, including the introduction of fast-growing broadleaved tree species within native stands. Here, we studied how enrichment of temperate European Scots pine (Pinus sylvestris) forest by North-American northern red oak Quercus rubra impacted macronutrient concentrations in two long-lived and dominant components of the forest understory: bilberry Vaccinium myrtillus and lingonberry V. vitis-idaea. Study sites were located in forest complexes (central Poland) which occupy continuously reforested lands (hereafter ancient forests) as well as post-agricultural lands (recent forests), all suitable for mesic pine forests. Samples of bilberry and lingonberry leaves, stems, and fruits were collected in pine stands and in adjacent Scots pine-red oak stands, in both ancient and recent forests. Concentrations of macronutrients (C, N, P, K, Ca, S, and Mg) in aboveground biomass components were analysed using standardized chemical procedures. The study revealed intra- and interspecific (bilberry vs. lingonberry) differences in concentrations of all nutrients in leaves, stems, and fruits, except for invariable C concentrations. Macronutrient accumulations in plants were decreased by land-use discontinuity and favoured by enrichment of tree stands by Q. rubra. The estimated macronutrient pools were much higher for V. myrtillus than V. vitis-idaea in all forest types studied. They were lower in forests enriched with Q. rubra, both ancient (up to 25.5% for bilberry and 99.9% for lingonberry) and recent (46.9% and 99.9%, respectively), as well as in recent pine forest (46.6% and 81.1%, respectively) than in ancient pine forest. Higher K and S pools (39.3% and 6.5%, respectively) noted for bilberry in an ancient forest with Q. rubra were exceptions. Despite more effective accumulations of elements at the species level, macronutrient pools of Vaccinium myrtillus and V. vitis-idaea decreased significantly in the presence of introduced Q. rubra due to negative impacts of this broadleaved tree on bilberry and lingonberry cover and biomass. Therefore, the limitation of alien Q. rubra planting in sites of mesic pine forest with the abundant occurrence of V. myrtillus and/or V. vitis-idaea is recommended.

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The analysis of PAHs nitrogen derivatives in the sewage sludges of upper Silesia, Poland

The dimethylformamide extracts from sewage sludges from a chosen sewage — treatment plant in highly industrialized region of Poland were investigated. Using the column chromatography with Al₂O₃ and silicic acid as the stationary phases, the fraction of azaarenes has been separated. GC-MS analysis of azaarenes fraction made it possible to identify 10 azaarenes and several of their alkyl derivatives, which dominate in the organic matter extracted from sewage sludges. The silicic acid column chromatography in connection with the reduction of nitroarenes and derivatization with pentafluoropropionic acid anhydride yielded an enriched nitrofraction. Nitroarenes present in this fraction as amide derivatives were also analysed by GGMS method. There was found presence of 3 nitroarenes and their methyl derivatives.     

Optimisation of sodium and potassium concentrations and pH in the artificial seminal plasma of common carp <Emphasis Type="Italic">Cyprinus carpio</Emphasis> L.

The effect of sodium and potassium concentrations as well as optimal pH on the motility of common carp Cyprinus carpio L. sperm during short-term storage in artificial seminal plasma (ASP) was investigated. Sperm was collected from individual males (n?=?5) and each sample diluted tenfold (1:9) in ASP (sperm:extender) containing 2 mM CaCl₂, 1 mM Mg₂SO₄ and 20 mM Tris at pH 8.0 and supplemented by the following concentrations of sodium and potassium (mM/mM): 0/150, 20/130, 40/110, 75/75, 110/40, 130/20 and 150/0. The osmolality of all ASP variants was set at 310 mOsm kg^?1. Sperm motility was measured using a CASA system during 72 h of storage. Immediately after dilution, sperm motility was high (90%) both in each variant and in the control group (fresh sperm). After 72-h storage, the highest sperm motility was noted in ASP containing 110 mM NaCl and 40 mM KCl. No differences were found in the motility of samples preserved within the pH range of 7.0–9.0. Our data suggest that for the short-term storage of common carp sperm, whereas the pH of the solution does not play a crucial role, a specific potassium concentration of around 40 mM is required.     

Motility parameters of perch spermatozoa (Perca fluviatilis L.) with cryoprotectors addition

The addition of cryoprotectants during the freezing of semen in liquid nitrogen protects spermatozoa from the negative influence of freezing. Every species needs an appropriate cryoprotectant that has to be experimentally selected. Semen obtained from five perches was diluted with the Kobayashi buffer solution at 1:9 ratio. To determine the influence of cryoprotectants on spermatozoa motility parameters, the same type of buffer solution was applied with the addition of methanol, dimethyl sulfoxide (DMSO) and dimethylacetamide (DMA) using the concentration of 10, 5, 2.5 %, respectively, glycerol (15; 7.5 %), sucrose and trehalose (0.45; 0.225; 0.113 M). After the preparation of such tests, parameters of spermatozoa motility were measured, using the CASA system (Image House CRISMAS Company Ltd.). Among used cryoprotectants, methanol did not cause any effect on the sperm motility parameters. The lowest percentage concentrations of DMA, DMSO, glycerol, sucrose and trehalose did not significantly influence the percentage of motile spermatozoa. Higher concentrations of these compounds considerably lowered all motility parameters. As for glycerol and saccharides, their addition resulted in the lowering of the spermatozoa motility possibly due to a higher viscosity of the solution. However, DMA and DMSO were most probably toxic to perch sperm cells. The obtained results indicate that the best cryoprotectant to be used with perch spermatozoa is methanol.