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A non-invasive laser fiber-optic method based on infrared sensors for heart rate (Hr) recording was applied to assess the physiological condition of Pinna nobilis. During 2017, the specimens of P. nobilis were sampled at three sites within the Boka Kotorska Bay, Montenegro and used for ex situ experiments with short-term reduction/restoration of ambient salinity to evaluate their physiological adaptive capacity based on heart rate recovery time (Trec). Mean Trec for specimens from Sv. Nedjelja (reference site), Dobrota and Sv. Stasije were 72 ± 3, 91 ± 7 and 117 ± 15 min, while the coefficients of variation (CV) were 0.12, 0.13 and 0.17, respectively. Resting heart rate (Hrrest) and Trec showed statistically significant differences between the groups of mussels from Dobrota and Sv. Stasije in comparison to the reference site. Statistically significant correlations were observed between Trec and shell length/width, which was not the case in comparison between Hrrest and shell length/width. The lower adaptive capacity within the P. nobilis specimens from Dobrota and Sv. Stasije in comparison to the reference site could occur due to stress induced by deterioration of environmental conditions, which could have led to impairment of the physiological state of the mussels evaluated by Hr. All the specimens of P. nobilis survived the experimental treatments; afterwards, they were successfully transplanted at the Dobrota site. The experimental unit with sensor technology applied in this study can provide Hr recording in real time and could have an application in monitoring the physiological/health state of P. nobilis individuals maintained in aquaria.

In this study we have performed a comprehensive genotoxicological survey along the 900 rkm of the Sava River. In total, 12 sites were chosen in compliance with the goals of GLOBAQUA project dealing with the effects of multiple stressors on biodiversity and functioning of aquatic ecosystems. The genotoxic potential was assessed using a complex battery of bioassays performed in prokaryotes and aquatic eukaryotes (freshwater fish). Battery comprised evaluation of mutagenicity by SOS/umuC test in Salmonella typhimurium TA1535/pSK1002. The level of DNA damage as a biomarker of exposure (comet assay) and biomarker of effect (micronucleus assay) and the level of oxidative stress as well (Fpg-modified comet assay) was studied in blood cells of bleak and spirlin (Alburnus alburnus/Alburnoides bipunctatus respectively). Result indicated differential sensitivity of applied bioassays in detection of genotoxic pressure. The standard and Fpg-modified comet assay showed higher potential in differentiation of the sites based on genotoxic potential in comparison with micronucleus assay and SOS/umuC test. Our data represent snapshot of the current status of the river which indicates the presence of genotoxic potential along the river which can be traced to the deterioration of quality of the Sava River by communal and industrial wastewaters. The major highlight of the study is that we have provided complex set of data obtained from a single source (homogeneity of analyses for all samples).

Distribution of 17 chemical elements in gills, muscle, and liver of the European perch (Perca fluviatilis) and black bullhead (Ameiurus melas) from the Sava Lake (Serbia) was studied to detect bioaccumulation patterns in relation to the species’ diet and trophic level. Concentrations of Ba, Cd, Co, Cr, Li, Ni, Pb, B, and Se were below the detection limits. Concentrations of Al, Fe, Mn, Sr, and Zn were higher in gills of the black bullhead; As, Mo, and Sr were higher in liver of the European perch; Fe and Zn were higher in liver of the black bullhead. In muscle, a significant difference between species was found only for Sr. Copper was detected only in liver of the black bullhead. Similarity in elemental concentrations in both species could be explained by a relatively similar diet of these two species, while the differences, especially in gills, could be explained by different habitat preferences.

Freshwater bodies receive high levels of different toxicants. Since fish are typically situated at the top of aquatic food chains, they have a good potential to be used as indicators of water pollution. Assessment of the presence of pollutants and their toxicity can be efficiently performed by the combined use of analytical chemistry, bioassays and applied mathematics. In this study, we present the general approach of the integrated use of different fish related parameters to assess the status and pollution levels of waterbodies. We discuss our previous experiences within the field of analytical toxicology, toxicological pathology and toxicity testing, as well as biomathematical and statistical methods that are able to provide for integration of results acquired by each of the specific methods. We discuss advantages and shortcomings of each of the methods, and present necessary future steps in the method development. Since the industrial and domestic wastewaters in Serbia are still not processed before being released into watercourses, they pose a serious risk for aquatic ecosystems and public health. Consequently, described pollution indicators and genotoxicity parameters represent an essential tool for efficient monitoring of aquatic ecosystems. Methodological approach presented here might be of interest for scientists and managers dealing with the ecotoxicological research and monitoring of freshwater ecosystems.

The aim of this study was to analyze 16 trace elements (Al, As, B, Ba, Cd, Co, Cr, Cu, Fe, Li, Mn, Mo, Ni, Pb, Sr, and Zn) in different barbel (Barbus barbus) tissues and to detect the presence of genotoxic effects in erythrocytes with the alkaline comet assay. Barbel specimens were collected in the Danube river near Belgrade, Serbia, where the discharge of untreated communal and industrial wastewaters is likely to produce negative effects on fish residing in this area. The highest concentrations of Sr, Mn, Fe, Ba, B, and Al were found in gills, Mo and Cu in liver, and As and Zn in gonads. Concentrations of Zn and Fe were above maximum acceptable concentrations (MACs) in a number of gonad, gill, and liver samples. Three-year-old barbel specimens had higher tail moment and Zn concentrations in gills (1.71 and 51.20 μg/g dw, resp.) than 5-year-old specimens (0.85 and 42.51 μg/g dw, resp.). Results indicate that the younger barbel specimens might be more suitable for the monitoring of environmental pollution.

Sponges in the large rivers within the Danube River Basin (DRB) have not been adequately studied. Hence, the aim of this work was to undertake an investigation on the distribution of sponge species in the Danube and Sava rivers. Out of 88 localities covered by the study, sponges were found at 25 sites only (46 samples in total). By using morphological (light and scanning electron microscopy) and genetic (28S rDNA sequencing) analysis, four species were determined: Ephydatia fluviatilis (Linnaeus, 1759), Spongilla lacustris (Linnaeus, 1759), Eunapius fragilis (Leidy, 1851), Trochospongilla horrida Weltner, 1893. In the Danube, the predominant species was found to be E. fluviatilis making approximately 80% of collected samples, while in the Sava River S. lacustris dominated, representing 46% of the river sponges. Our work represents one of the few studies on freshwater sponges within the DRB from long stretches of the large lowland rivers (more than 2500 km of the Danube River and about 900 km of the Sava River). Moreover, molecular analysis for the identification of freshwater sponges was applied on the material collected from a wide area, thus contributing to the systematic studies on the distribution and abundance of the European freshwater invertebrate fauna in general.

Electrophysiological monitoring of saccadic eye movements in patients with hypoxic-ischemic encephalopathy was carried out. Externally guided saccades (prosaccades) were recorded using a patented hardware-software complex for studying a subject's physical activity. Recordings were performed in two independent experimental procedures - for saccades separately and when they were coordinated with movement of the head and hand. In both cases statistically significant differences of latent period and duration of saccadic eye movement were detected for hypoxic-ischemic encephalopathy subjects in comparison with healthy controls of the same age (p < 0.05). Jerking and deviation of eyes after gaze fixation on a target were often present in hypoxic-ischemic encephalopathy subjects. In some cases saccades of these subjects were asymmetrical among themselves. Hypoxic-ischemic encephalopathy induced changes in the parameters of autosaccades were also found They were expressed through instability of gaze fixation periods, sometimes asymmetric eye movements, slow gaze shift from one target to another, and disturbance of gaze stabilization (jerking of eyeballs during the saccadic period).