Miroslav Ćirković

Non-native and translocated fish species in Serbia and their impact on the native ichthyofauna

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 currently occupy more than 51% of Serbian territory while 5 of them occupy between 21–50% of territory. This paper reviews impacts of introduced freshwater fish in Serbia based on collected data.

Organochlorine pesticides in canned tuna and sardines on the Serbian market

ABSTRACT The aim of this study was to determine the level of organochlorine (OC) pesticides in 57 samples of canned tuna and 31 samples of canned sardines in vegetable oil, collected from supermarkets in Serbia. OC pesticides α-HCH, β-HCH, δ-HCH, dichlorodiphenyltrichloroethane (DDT), DDE, DDD, dielderin, endosulfane I, endosulfane II, endosulan sulfate, endrin, endrin ketone, heptachlor, heptachlor epoxide, lindane, aldrin, metoxichlor, cis-chlordane and trans-chlordane were determined using a GS-MS method. The highest concentrations (µg kg−1, arithmetic means) in canned tuna were for δ-HCH (60.6 ± 97.0) and p, p´-DDT (55.0 ± 25.1), while the corresponding values in canned sardines were for δ-HCH (90.7 ± 102.7) and endosulfane II (78.0 ± 145.9). Mean level for the sum of endosulfans was above the maximum limit in canned sardines (85.0 µg kg−1). Also, dieldrin (39.7 µg kg−1) was measured above the ML.

COMMON FISH SPECIES IN POLYCULTURE WITH CARP AS CYPRINID HERPES VIRUS 3 CARRIERS

Cohabitation studies with common carp were conducted to determine whether the Cyprinid Herpes Virus 3 can infect and establish a productive infection in fish species that according to available data, are not susceptible to this virus. In order to examine if other fish species can contribute to further spreading of the virus, goldfish, silver carp, grass carp, prussian carp and tench were exposed to CyHV-3 through cohabitation with infected carp without clinical symptoms. After this period they cohabitated with naive carp for two weeks and were examined for CyHV-3 by PCR. Our results showed that CyHV-3 was present in the organs of these fish species and also in organs of naive carp after two weeks in cohabitation, suggesting that CyHV-3 may cause latent infection, and also that has a potential to infect a broader host range than it was believed before. Our study adds on better understanding of CyHV-3 transmission not just in its primary host, but also suggests the importance of common fish species in polyculture with carp in the epidemiology of CyHV-3. [Projekat Ministarstva nauke Republike Srbije, br. TR31075 i br. TR-31011]

Fish Product–Borne Histamine Intoxication Outbreak and Survey of Imported Fish and Fish Products in Serbia

Histamine levels in fish and fish products are regarded as a primary criterion for food safety, considering the effects of histamine on human health. The aim of this research was to describe a case of massive histamine intoxication in Serbian children and to provide relevant information regarding the presence of histamine in imported marine fish and fish products available in the Serbian market. In January 2014, an incident of foodborne illness occurred in 28 children (aged 2 to 5 years) who consumed canned sardines in a kindergarten in Vojvodina province, northern Serbia. The diagnosis was established based on anamnestic data, epidemiological data, and clinical symptoms and confirmed by positive histamine finding in the incriminated sardines. Substantially high histamine levels (>300 mg/kg) were detected in seven of the nine examined units of these canned sardines. In addition, during an official veterinary border control from January 2013 to January 2015, 273 lots in total, including 2,457 fish and fishery product units, were analyzed using enzyme-linked immunosorbent assay. Even though only nine (3.29%) of all examined lots were declared as unsafe for human consumption, the presented case of histamine intoxication strongly suggests the importance of border inspection and comprehensive control of each imported lot.

The first determination of Eustrongylides excisus Jägerskiöld, 1909 — larvae (Nematoda: Dioctophymatidae) in the pike-perch Sander lucioperca in Vojvodina (Serbia)

Twenty-one specimens of pike-perch (Sander lucioperca) were caught in the Danube-Tisa-Danube Canal in the city area of Novi Sad for parasitological examination. The presence of nematodes in the muscles was revealed in three fish. The parasites were identified to belong to the species Eustrongylides excisus, for which the pike-perch is a paratenic host. This finding represents the first determination of the larvae in the pike-perch in Serbia. The pike-perch is infected by ingestion of benthos- or plankton-eating fishes, the second intermediate hosts harbouring the fourth-stage nematode larvae. E. excisus is pathogenic to humans, who may be infected by consuming raw or undercooked fish.

Heavy metals and PAHs in canned fish supplies on the Serbian market

ABSTRACT The aim of this study was to determine the level of heavy metals and polycyclic aromatic hydrocarbons (PAHs) in 57 samples of canned tuna, 25 samples of canned sardines, and 16 samples of canned smoked sprouts, collected from supermarkets in Serbia. Heavy metal levels (lead, cadmium, mercury, arsenic, iron, copper, and zinc) were determined using an inductive coupled plasma mass spectrometry method. Sixteen analysed PAHs were determined using a gas chromatography–mass spectrometry method. The trace elements in canned fish were in the range (mg kg−1) of 0.01–0.28 for lead, 0.003–0.08 for cadmium, 0.007–0.64 for mercury, 0.17–3.73 for arsenic, 3.88–52.2 for iron, 0.2–5.95 for copper, and 1.35–44.5 for zinc. Total PAH levels reached 17.67 µg kg−1 in canned tuna and 15.12 µg kg−1 in sardines, whereas in smoked sprouts it amounted to 57.19 µg kg−1. Some of the samples contained cadmium, arsenic, copper, and benzo(a)pyrene above the limits as set by the European and Serbian legislation.

The establishment of the cell culture of preadipocytes of common carp (Cyprinus carpio L.)

Common carp is the most important freshwater fish in aquaculture in Republic of Serbia. Excess fat deposition in the meat and abdominal cavity of farmed carp can affect carp flesh quality, dressing percentage and consequently restrict the further development of aquaculture production. The reasons for lipid deposition in carp flesh and around visceral organs are not well known, and it is important to develop method which would enable us to understand process which occurs in common carp lipid cells. The aim of this study was to establish a new model of common carp preadipocytes and evaluate proliferation and differentiation capacity of carp preadipocytes in vitro. The establishment of the cell culture of preadipocytes of common carp could serve as a valuable tool for studying fat metabolism in this fish species.

The role of allochthonous (non-native) fish species in Serbian aquaculture

Fish farming is the only type of aquaculture in Serbia. Fish farming is mostly carried out in cyprinid and salmonid (trout) fishponds (over 95% of the total fish produced), with considerably lower ichthyoproduction being practiced in cages and some bodies of open water such as reservoirs and channels. Serbian aquaculture currently includes 12 fish species, 4 of which are allochthonous (non-native). With the exception of the rainbow trout (Oncorhynchus mykiss) and, to a certain extent, grass carp (Ctenopharyngodon idella), silver carp (Hypophthalmichthys molitrix) and bighead carp (Hypophthalmichthys nobilis), allochthonous fish species have no economic importance. The presence and abundance of certain allochthonous species in fishponds and open waters have a negative effect on the total ichthyoproduction.

A contribution to the data on tench (Tinca tinca L., Cyprinidae, pisces) distribution in Serbia

The studies on the ichthyofauna of Serbia that have been conducted so far indicate the sporadic tench (Tinca tinca L.) presence in typical habitats. The hydroenvironmental conditions necessary for the survival of this fish species are highly variable and, generally, are more favourable in the northern part of the country (the Vojvodina Province). Although the tench presence has been registered at over 30 sites, there is a tendency of a decrease in population abundance. This is due to the reduction of the surface area of the macrophyte-covered flood zones induced by the damming and regulation of rivers, high water level fluctuations, and water amount reduction in the majority of watercourses, a massive increase in the number of allochthonous phytofagous species, reservoir sediment deposition, water quality deterioration and other factors. The tench conservation status in Serbia is officially designated as Low Risk - Least Concern. It may be transferred to a higher category if the tendency towards deterioration of survival conditions for the species should continue.

Content of Polycyclic Aromatic Hydrocarbons in Smoked Common Carp (Cyprinus Carpio) in Direct Conditions Using Different Filters vs Indirect Conditions

Abstract In this study, the common carp fish were smoked in direct and indirect smoke chambers. Direct smokings in craft chamber were conducted in four ways: smoked without filter (Fo), with zeolite filter (Fz), filter with granular activated carbon (Fc) and gravel filter (Fg). The content of 16 different PAHs in smoked common carp was analyzed using GCMS method. Addition of zeolite, activated carbon and gravel filters significantly reduced PAH levels (P < 0.05). Levels of naphthalene, acenaphthylene, fluorine, phenanthrene and fluoranthene were reduced using zeolite, activated carbon and gravel filters by 42.14, 40.64, 42.5 (Naph), 49.81, 48.96, 48.96 (Acy), 32.71, 30.79, 26.15 (Fln), 28.79, 31.68, 18.34 (Phe) and 4.14, 3.87 and 1.12 (Flt) µg/kg, respectively. The addition of zeolite and activated carbon filters reduced amount of anthracene by 15.28 and 11.89 µg/kg and amount of pyrene by 1.25 and 0.6 µg/kg, while addition of gravel filters did not influence significantly these PAHs (P > 0.05). However all filters decreased acenaphthene, benz[a]anthracene and chrysene below detection limits. Zeolite was the most effective adsorbent for PAHs. All samples were under maximum limit of BaP (2 μg/kg) and PAH4 (12 μg/kg) set by European Commission Regulation 835/2011. Based on results in the present study it can be stated that common carp smoked in both direct and indirect conditions can be considered to be safe for consumption.