Aleksandar Hegedis

• Institute for multidisciplinary research

Northern pike specimens of 0+, 1+, and 2+ age classes were collected in June 2013 from the Vizelj channel near Belgrade (Serbia). Inductively coupled plasma optical spectrometry (ICP-OES) and atomic absorption spectrometer SpectrAA 220 were used for analyzing concentrations of As, Cr, Cd, Co, Cu, Fe, Sr, Pb, and Zn, as well as Hg in muscle, gills,...

The black bullhead is an invasive species that forms dense populations and has a negative impact on the native ichthyofauna. Recent studies indicate that it is one of the most dominant invasive fish species in Serbian waters. Feeding habits based on stomach contents of individuals caught in Lake Sava were analyzed as a first step towards evaluating...

Water and sediment samples were collected during summer of 2017 from the reservoirs: Garaši, Vlasina, Perućac, Zaovine, Međuvršje, and Sava Lake. Analysis of As, B, Cd, Cr, Cu, Fe, Hg, Mn, Ni, Pb, and Zn were performed using inductively-coupled plasma optical emission spectrometry (ICP-OES). Accumulation of elements in water and sediment samples va...

The Danube River basin represents a hotspot for the European freshwater diversity. The Danube in Serbia is characterized by a significant level of fish diversity, as well as by economically important fish resources. However, the Danube fish fauna is facing a number of adverse anthropogenic impacts, such as unsustainable fishery, habitat loss and fr...

The surface area of Montenegro’s portion of the Black Sea drainage basin is 7075 km², or 0.9% of the entire basin, and is made up of the rivers Tara, Piva, Lim, Ćehotina and Ibar, and Lake Plav. The major polluters of watercourses are wastewaters and solid waste from inhabited settlements. According to water categorization regulations, the rivers o...

Concentrations of As, Cd, Cr, Cu, Hg, Pb, and Zn in sediment samples and muscle tissue of the European perch were analyzed using inductively-coupled plasma optical emission spectrometry (ICP-OES), with the aim to assess the potential ecological (RI) and human health risk, and the degree of contamination (Cd) of three types of reservoirs in Serbia,...

The life‐history traits and population dynamics of the black bullhead Ameiurus melas (Rafinesque) were studied monthly from August 2009 to December 2012 in Lake Sava in Belgrade (Serbia). This period included a mass mortality event in May 2011 and subsequent population recovery during 2012. Available evidence suggests the mass mortality was caused...

During the last decades in the freshwater system in Serbia 32 allochthonous fish species appeared, and they can be divided into five groups according to their region of origin: Asian, Ponto-Caspian, North American, South American, and Europe without Ponto-Caspian region. The Asian and Ponto-Caspian species are the most numerous. In the first group...

Species diversity is related to the function of ecological systems and it helps to understand the effects and mechanisms of environmental disturbances. Rise of concern regarding the water quality and water availability lead to a development of effective ecological tools capable of detecting the extent of anthropogenic impact. The significance of fi...

Chub (Squalius cephalus) specimens were collected in Korenita River seven months after spillover from the waste water of antimony mine tailing pond and compared with chub living in Kruščica reservoir (intended for water supply) and Međuvršje reservoir (influenced by intense emission of industrial, urban and rural wastewater). Concentrations of 15 e...

The effects of physical factors on fish catch in the Serbian part of the Danube River were studied for period of six decades. The data on total catch for the Danube River from river kilometre 845 to river kilometre 1433 were collected from Statistical Office of the Republic of Serbia, while water level and water temperature data were collected from...

Amur sleeper (Perccottus glenii) represents invasive species to European waters, where it can have negative impact on eggs and larvae of autochthonic fish species, as well as aquatic macroinvertebrate and larval amphibians. Our research includes 85 specimens from channel near Veliko Gradište (Serbia), during 2015-2016 survey. Body length of specime...

The concentrations of As, Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Se and Zn in the muscle, gills, liver and intestine of the wels catfish (Silurus glanis) from the Danube River were analyzed by inductively coupled plasma mass spectrometry (ICP-MS). The aim of the study was to determine whether in complex muscle/skin, gill filament/gill arch, proximal/d...

The analysis of 18 elements in muscle, liver, gills, and gonads of sichel (Pelecus cultratus), ruffe (Gymnocephalus cernua), and European perch (Perca fluviatilis), caught at a polluted segment of the Danube River near Belgrade, was carried out with the aim to expand the knowledge about the ecotoxicology of these species for monitoring purposes and...

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 detecti...

There is a lack of adequate estimates of the fish stocks in the Belgrade city area, Serbia, as well as of the current fishery pressure on fish diversity and of the contamination level of fish meat. These factors obstruct efforts to conduct valorisation of the current state and potential development of this resource. During 2012 and 2013, an assessm...

Studies of metal accumulation in fish are mainly focused on the muscle tissue, while the metal accumulation patterns in other tissues have been largely neglected. Muscle is not always a good indicator of the whole fish body contamination. Elemental accumulation in many fish tissues and organs and their potential use in monitoring programs have not...

One of the purposes of this study was to examine whether b-wave measurements can be used in the evaluation of scotopic spectral sensitivity in Prussian carp measurements when the eyes were surgically deprived of cornea, lens, and most of the vitreous. Another goal was testing the new fitting procedure for A2-based photopigments. Using fitted amplit...

The antiradical activity of the freshwater bryozoan Hyalinella punctata water extracts (two samples, seasonal collection) was evaluated by using electron paramagnetic resonance spectroscopy against hydroxyl (√OH), superoxide anion (√O2(- )), methoxy (√CH2OH), carbon-dioxide anion (√CO2(- )), nitric-oxide (√NO) and 2,2-diphenyl-1-picrylhydrazyl (√DP...

Huchen, Hucho hucho (L.), also known as Danube salmon, is an iconic, endemic species inhabiting the Danube basin of Central Europe. Historically, the Danube huchen inhabited a significant portion of the Danube drainage basin stretching to the Iron Gate and the majority of large and medium-sized tributaries. Larger populations in the natural zoogeog...

Pikeperch (Sander lucioperca), European catfish (Silurus glanis), common carp (Cyprinus carpio), and gobies (Neogobius gymnotrachelus, Neogobius melanostomus) were collected from the Danube River (Belgrade section), and samples of liver, muscle, or whole-body composites (in the case of gobies) were analyzed for As, Cu, Fe, Hg, Mn, and Zn with induc...

The Danube River in the vicinity of the city of Belgrade receives large amounts of untreated or poorly treated communal and industrial waste waters. The aim of this study was to assess elemental accumulation patterns in a number of economically important fish species in this area that belong to different trophic levels. Concentrations of 17 element...

The distribution and contents of organochlorine pesticides (OCPs) and congeners of polychlorinated biphenyls (PCBs) were analyzed in Bream (Blicca bjoerkna) and Barbel (Barbus barbus) from the Danube River, near Batajnica. The analysed compounds were 16 OCPs (α-Hexachlorocyclohexane (α-HCH), β-Hexachlorocyclohexane (β-HCH), Hexachlorobenzene (HCB),...

The objective of the present study was in vitro evaluation of radioprotective activity of the freshwater bryozoan Hyalinella punctata on cultured human peripheral blood lymphocytes after irradiation with 2 Gy of 60Co g-rays. Since its water extract at concentration 0.001 mg/ mL reduced the incidence of radiation-induced micronuclei for almost 30 %,...

The antimicrobial activity of the freshwater bryozoan Hyalinella punctata (Hancock, 1850) was tested by microdilution method against eight bacteria and eight fungi for the first time. All five crude extracts (hexane, acetone, dimethyl sulfoxide, methanol and water) showed good antibacterial and antifungal potential in vitro wherein the acetone extr...

The immunomodulatory and anticarcinogenic activity of the freshwater bryozoan Hyalinella punctata methanolic extract (MEx) was evaluated in vitro on selected biosystems for the first time. Murine lymphocytes and macrophages were used for testing of MEx effects on cell proliferation and nitric oxide (NO) production, respectively, while human cancer...

Data on the presence of invasive species are often scarce, especially during the initial period following their introduction, when population abundance and species detectability are both still very low. In such cases, sporadic sightings in their newly occupied territory are often the only available information about their presence and distribution....

A total of 22 fish species have been introduced into the inland waters of Serbia, either intentionally or accidentally. This paper provides a summary of data concerning time and reason of introduction, mode of expansion, degree of acclimatization, impact on native fish and estimated area of recent distribution. Four of the non-native fish species c...

SummaryA sample of 198 asp (Aspius aspius) was collected over a 28.5 km long section of the Danube River, upstream and downstream from the mouth of the Sava River, in order to provide information on population structure, diet, growth, and condition of this species. Total body lengths of sampled fish were 90–405 mm, and body weights 5–567 g. The sam...

Carps (Cyprinus carpio) were farmed on a river hopper barge at two stocking densities, 10 and 20 individuals per m3. A comparison of average weights, specific growth rates and weight distributions was performed. The obtained results show that there was no statistically significant difference in any of the parameters studied with regard to stocking...

Three localities, representing three distinct coastal areas, were investigated: 1. the mouth of the Sutorina River; 2. the mouth of the Jaška River; 3. the mouth of the Bojana River (right branch). Regarding the composition of young mullet assemblages, Lisa saliens, Lisa ramada and Lisa aurata were dominant at the first locality; L. aurata and Chel...

Specimens of Pontic shad (Alosa pontica Eichwald, 1838) were collected during April and May of 2006 in the Danube River (rkm 863) just downstream of the Iron Gate (Djerdap) II dam. Twenty-eight scales and 30 vertebrae were prepared and given to five interpreters with fish aging experience of from 3 to 30 years and with shad aging experience of from...

Whereas earlier Amur sleeper (Perccottus glenii) findings in the Danube River were only single specimens, data reported in this study represent the first record on establishment of a local population. An overview of the spread of the Amur sleeper in the Danube River basin is also presented.

The action spectrum of the electroretinographic (ERG) b-wave and the unmasked late receptor potential (LRP) were measured under a variety of conditions (isolated eyecup, detached retina, b-wave recording in fresh preparations, LRP measurements after low-temperature aging, dark and light adaptation). It was shown that in the dogfish, Scyliorhinus ca...

Radoslav K. Andjus was a professor of physiology and biophysics at the University of Belgrade, Serbia, from 1953 to 1992. He was an elected member of the Serbian Academy of Sciences and Arts, the International Academy of Astronautics, and the Montenegrin Academy of Sciences and Arts. He published over 190 papers in domestic and international journa...

The characteristics of glass eel migration at the mouth of river Bojana have been investigated by seasonal field studies from February to April 1998. Samples were collected by two fyke nets, one on each riverside, for 12 hours each night. A total of about 3,300 individuals were caught. In this work we present the results obtained from three success...

On the 14th of June, 2005, in the Danube side channel "Jojkić" (N 44°50'33.1’’, E 20°27'46.1’’) near Belgrade, we recorded the presence of A. melas, ranging in weight (W) from 11.2 g to 135.6 g, and standard length (Ls) from 70 mm to 173 mm. Specimens were obtained from professional fishermen, who caught them with gill nets, as well from...

Two specimens of the Chinese mitten crab, Eriocheir sinensis, were found in the Serbian part of the Danube River (1995, 1084\,km of the watercourse and 2001, 1174\,km). Description, biology, origin and distribution of this species, as well as potential impact to the aquatic ecosystems are discussed. These are first records of this invasive crab in...

The first record of Pseudorasbora parva in the Balkan region was in 1977 in Sasko Lake, Montenegro and in 1978 it was found in Serbia. Since then, this species has spread to almost all lowland rivers and has become a permanent member of the ichthyofauna in Serbia and Montenegro.

All waters of the Aegean drainage in South-East Serbia are inhabited by the Macedonian trout Salmo macedonica (KARAMAN, 1924). Eastern barbel Barbus cyclolepis (HECKEL, 1814) and chub Leuciscus cephalus (L., 1758) were found only in the Dragovištica River and the minnow Phoxinus phoxinus (L., 1758) was recorded in the most downstream sections of th...

About 10000 huchen larvae, obtained by artificial spawning, were introduced on 28 May 1995 into the River Tresnjica, a tributary to the River Drina, using procedures applied routinely by local fishing associations. During next two months, only 33 fry were caught in the river. Nevertheless, valuable information has been obtained for the first time o...

Endohelminths of Mediterranean barbel (Barbus peloponnesius petenyi) from tributaries of the Kolubara River were studied as a part of ichthyoparasitological research in Serbia. Fish specimens from the River Gradac were collected in 1987, and from the rivers Gradac, Jablanica and Pocibrava in 1995. The 117 Mediterranean barbel studied specimeens' we...

1 Institute for Marine Biology, Kotor; Yugoslavia 2 Hegediš Aleksandar, Miükoviü Branislav, Nikþeviü Miroslav, Damjanoviü Ilija and Andjus K. Radoslav (1998): Eels and mullets in coastal waters of Montenegro: Basic ecological data . -Iugoslav. Physiol. Pharmacol. Acta, Vol. 34, 417-428. The coastal region of Montenegro is about 300 km long, from ri...

The aim of this study is to explore the possibilities of introducing the new technology of intensive carp (Cyprinus carpio) farming in a floating vessel. The experiment was conducted on an out-of-use hopper barge on the Danube. Water was pumped in from the Danube using two pumps with a total power of 1 kW. The farming was conducted in two barge com...