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Twenty non-indigenous fish species were recorded in the Danube River. The manner of their introduction, vectors, pathways, as well as invasive status are discussed. The major modes of introduction and translocation were found to be aquaculture and fish stocking. The main environmental consequences of the spread of alien fish are related to changes in the structure and functioning of the fish community and to the introduction of non-indigenous parasites. [Projekat Ministarstva nauke Republike Srbije, br. ON 173025, TR 37009 and III 43002 and European Commission 6th Framework Program: Integrated Project ALARM (contract GOCE-CT-2003-506675)]

Sinanodonta woodiana (Lea, 1834), Chinese pond mussel (Bivalvia: Unionoida: Unionidae) is one of the most invasive aquatic macroinvertebrate species found in Europe. We report the Chinese pond mussel for the first time in Montenegro, in August 2012, in Lake Šasko (Adriatic part of the Central Mediterranean subarea). One specimen of the Chinese pond mussel was observed in a habitat with a predominantly silt-clay substrate. The main pathway of species introduction was evaluated to be via fish stocking. [Projekat Ministarstva nauke Republike Srbije, br. III 43002 i br. ON 173025]

Research into the ichthyofauna of the Vlasina Lake reservoir in south Serbia, which is part of the Danube basin, was carried out in 1993, 40 years after its formation. The results of the research reveal the presence of several species of fish belonging to the Adriatic and Aegean basin, such as Alburnus albidus, Rutilus basak, Scardinius graecus and Pachychilon macedonicus. These findings are of great importance from the aspect of conservation, because the species Scardinius graecus and Alburnus albidus are on the European list of endangered fish species. In the latest study of the Vlasina Lake reservoir ichthyofauna (70 years after its formation), the above-mentioned species were not found. However, the presence of naturalized populations of two species from the Adriatic basin were confirmed: Scardinius knezevici and Alburnus scoranza. These findings represent the first known areal expansion of these species, which are new to the ichthyofauna of Serbia, from the Adriatic into the Danube (Black Sea) basin.[Acknowledgments. The present work was supported by the Ministry of Education and Science of the Republic of Serbia (Projects No. 43002 and 173025).]

We report the discovery of Bothrioneurum vejdovskyanum Štolc, 1886 (Annelida: Oligochaeta: Tubificidae: Rhyacodrilinae) in Serbian freshwaters. Fifteen specimens were found in the middle course of the River Ibar (southern Serbia), at a locality where the macrolithal type of substrate and strong currents prevail. These organisms were found together with Stylodrilus heringianus (Claparede, 1862). They were among the most abundant Oligochaeta species. The species are described and its biology and distribution are discussed. The present record contributes to the knowledge on the general distribution of this rare species, particularly in the Balkans (southeastern Europe). [Acknowledgments. This work was supported by the Ministry of Education and Science of the Republic of Serbia, Projects No. ON 173025 and III 43002]

The aim of this study was to ascertain the possibility of using biological toxicity tests to monitor influent and effluent wastewaters of wastewater treatment plants. The information obtained through these tests is used to prevent toxic pollutants from entering wastewater treatment plants and discharge of toxic pollutants into the recipient. Samples of wastewaters from the wastewater treatment plants of Kragujevac and Gornji Milanovac, as well as from the Lepenica and Despotovica Rivers immediately before and after the influx of wastewaters from the plants, were collected between October 2004 and June 2005. Used as the test organism in these tests was the zebrafish Brachydanio rerio Hamilton - Buchanon (Cyprinidae). The acute toxicity test of 96/h duration showed that the tested samples had a slight acutely toxic effect on B. rerio, except for the sample of influent wastewater into the Cvetojevac wastewater treatment plant, which had moderately acute toxicity, indicating that such water should be prevented from entering the system in order to eliminate its detrimental effect on the purification process.

The aim of the study presented was to define trophic relationships within the benthic community according to functional feeding groups (FFG) in the Vlasina River (Southeast Serbia), with an attempt to use those results to describe the watercourse. In an investigation performed during 1996, a total of 125 macrozoobenthic taxa were identified, 95 of which were included in FFG analyses. Although the investigated part of the river, in its physical and chemical characteristics, as well as characteristics of the benthofauna, generally corresponds to what could be expected, certain variations of faunal composition were observed along the river. Two groups of sites were separated by FFG analysis - sites on the upper section of the river and on a tributary (the Gradska River) comprised one group, while the remaining sites made up the other.

The mayfly (Ephemeroptera) fauna was studied during investigations of the Vlasina River (Serbia) conducted in 1996. Twenty-six species from 14 genera belonging to eight families were recorded. Compared to similar aquatic ecosystems in Serbia and Europe, the ephemeropteran fauna of the Vlasina River is characterized by high species diversity. Good water quality and habitat heterogeneity led to the observed richness of taxa. Based on fauna distribution, the middle reach of the river can be divided into three different segments - upper, middle, and lower. Distribution of the two dominant families, Heptageniidae and Baetidae, is emphasized. Representatives of Baetidae reach their highest density in July, while Heptageniidae were the most abundant in November. The recorded mayflies represent widely distributed European or Holarctic species.

This paper presents the results of studying length-weight gain using exponential regression analysis. The gain was analyzed in the Slano, Krupac, and Liverovići Reservoirs and in the Zeta River. Comparing growth at different localities, we found different weight gains. The greatest weight gain exists in the population from the Slano Reservoir. Growth in the first year of life is much more intensive in this area than in populations from the literature we compared it to. .

Heart wall tissue plays a crucial role in living organisms by generating the mechanical force for blood flow. This tissue has a complex internal structure comprised mostly of muscle cells, in which biochemical energy is transformed into mechanical active stress under rhythmical electrical excitation. The overall heart functioning depends, among other physiological conditions, on the mechanical properties of the tissue. Over the past centuries, experimental and theoretical investigations have been conducted in order to establish the constitutive laws governing wall tissue behavior. Regarding computational modeling, many material models have been introduced, from simple elastic anisotropic to more sophisticated ones, based on various formulations of strain potentials. We here present a novel computational model that directly employs experimental constitutive relationships. Therefore, we avoid any fitting of material parameters for a selected analytical form of the constitutive law. Hysteretic characteristics of the tissue are included, as well as either incompressibility or compressibility according to experimentally determined curves. Deformation is split into deviatoric and volumetric parts in order to handle compressibility. The correctness and accuracy of the model is demonstrated through simple cases for loading and unloading conditions. Furthermore, the model was implemented for left ventricle (LV) deformation, where the FE mesh was generated from echocardiography recordings. Here, a specific algorithm, which accounts for LV torsion, was introduced to determine trajectories of material points on the internal LV surface. Hysteresis of the constitutive curves was used to calculate mechanical energy of LV wall tissue deformation. For completeness, the fluid flow within the LV was computed as well. [ABSTRACT FROM AUTHOR]

Results of a 40 year-long investigation of room-temperature formation of compounds in 144 thin-film couples obtained by combining 23 metals (Ag, Al, Au, Bi, Cd, Co, Cr, Cu, Ga, Ge, In, Mg, Mn, Ni, Pb, Pd, Pt, Sb, Sm, Sn, Te, Ti, Zn) are presented. The data from published papers of the present and other authors have been complemented by unpublished data of the present authors. The systematized results and their analysis point to the following. In 39 couples, a total of 65 compounds are formed. The reactions of compound formation last from ∼1 min to ∼10 y, depending on the specimen type and procedure of film deposition. In the bulk–film specimens, the number of compounds formed is smaller and the reaction is slower than in the film–film specimens prepared by thermal evaporation. In the specimens with the sputtered top layer, a greater number of compounds is formed and the compound formation reaction proceeds more rapidly than in the couples prepared by thermal evaporation of both metals. The compounds formed can be transformed into others containing higher percentage of one of the constituents, until the specimen contains an excess of that constituent, provided that such compounds exist in the respective phase diagram. At the beginning of the reaction, compounds are formed in a broad concentration range, while at the reaction end the range is narrowed down, becoming close to that in the corresponding phase diagram. The optimum conditions for compound formation exist in the couples consisting of a high-melting metal and a low-melting one, provided that the potential compound is not high-melting. If the potential compound is high-melting, or if both metals in the couple have melting points in the same temperature range, no compound formation takes place at room temperature. In the couples consisting of a given high-melting metal and one of the low-melting metals, a linear relationship exists between the interdiffusion coefficient and the melting point of the low-melting metal. If, for a couple consisting of a high-melting metal and a low-melting one, there is a solid solubility range of the low-melting metal, during the course of long ageing, the compound formed is decomposed and the low-melting metal is amorphized. During the long ageing, the ambient atmosphere acts on the metal films (alone or in a couple) leading to formation of oxides, hydroxides or carbonates. The results obtained complement the low-temperature range results in the respective phase diagrams. [ABSTRACT FROM AUTHOR]

Research on the community of aquatic macroinvertebrates was carried out during 2005 and 2006 at four sampling sites along the Jablanica River, a right-hand tributary of the Kolubara River. Fifty-seven taxa were recorded in the course of the investigation. The most diverse group was Ephemeroptera, followed by Trichoptera and Plecoptera. Members of the Rhitrogena semicolorata group were the most abundant. Our results could be the basis for evaluation of the influence of damming of the Jablanica River on the status of its water and can serve as a model for studying the influ­ence of hydromorphological degradation of aquatic ecosystems.

This paper presents the first checklist of the family Chironomidae (Diptera) in Serbia, based on literature citations in two periods (1981/82 and 2010/11) and the unpublished data as well as material examined by the authors. Our survey ranges over the Central, Eastern, Southern and Southeastern parts of Serbia (Southern Morava River basin). We have listed 110 taxa distributed in following five subfamilies: Chironominae (39), Diamesinae (3), Orthocladiinae (48), Prodiamesinae (2) and Tanypodynae (16).