Suchergebnisse

Piria, Marina/0000-0001-6324-9282; Simonovic, Predrag/0000-0002-4819-4962; ; WOS: 000418927100009 ; Fish introductions, particularly in areas of high biological diversity and endemism, represent a major threat for biodiversity. In the Balkan Peninsula, 60 fish species have been introduced to date, of which 36 have become naturalized in inland waters. Since the Balkans are one of the world's 35 biodiversity hot spots, this large presence of alien fish species poses a serious threat for the stability of freshwater ecosystems and the survival of the native ichthyofauna and of aquatic biodiversity in general. The motivation for the introductions, and the historical timeline, varies among the Balkan states. Despite recent attempts to implement and align legislation aimed at preventing the introduction of potentially invasive species, and the implementation of rigorous controls of introductions and increased protection of open waters, the majority of current introductions remain intentional, primarily via aquaculture. This review article provides a historical overview of freshwater fish introductions, the motivation behind them and the current distribution of alien freshwater fishes in the Balkans. The ecological implications and future perspectives concerning alien fish species in the region are also discussed. ; University of Zagreb, Croatia; Ministry of Education, Science and Technological Development of Serbia [173025] ; University of Zagreb, Croatia; Ministry of Education, Science and Technological Development of Serbia, Grant/Award Number: 173025

We report digeneans (Diplostomidae, Crassiphialinae) in the endangered freshwater fishes Valencia letourneuxi and Valencia robertae, endemics of Western Greece. Digenean metacercariae occurred in two forms in the abdominal cavity, excysted and encysted, the latter attached to the gonads, liver and alimentary tract. Parasites were, using morphological and molecular techniques, identified as two representatives of Crassiphialinae, specifically part of the Posthodiplostomum-Ornithodiplostomum clade. The spatial, seasonal, and age class variation in parasite prevalence was examined. Autumn parasite prevalence varied between the six populations sampled (18.2 to 100%). Seasonal prevalence at the two sites sampled quadannually peaked in autumn and reached its lowest value in spring; prevalence increased with size to 100% in young adult fish. We did not find a correlation between prevalence and host sex. Overall parasites' weight averaged 0.64% of the host's, while parasite weight increased with host weight. A comparison of relative condition and hepatosomatic and gonadosomatic indices of infected and metacercariae-free specimens showed that infection did not have a significant effect on host body condition and reproduction. Regarding the parasite's life cycle, planorbid gastropods are proposed as potential first intermediate hosts in view of the host's diet and occurrence data of molluscs in the ecosystem. This is the first record of a diplostomid digenean in valenciid fishes and of representatives of the Posthodiplostomum-Ornithodiplostomum clade in a native Greek freshwater fish. Our findings are discussed in conjunction to fish conservation interventions, since parasites may contribute to the decline of endangered species. ; This research was conducted in the frame of a wider study on the ecology, biology, genetics, and diet of V. letourneuxi undertaken by scientists of HCMR and was partially funded by the European Union of Aquarium Curators (EUAC) in the frame of the project "Rapid Assessment of the Status of Valencia letourneuxi, the Greek Killifish" (2005-2009). This research received support from the SYNTHESYS Project (http://www.synthesys.info/) (GB-TAF-2984) which is financed by European Community Research Infrastructure Action under the FP7 Integrating Activities Programme. N.K. and M.P.M.V. are supported by the Czech Science Foundation [P505/12/G112 (ECIP)]. The authors wish to thank Andrea Waeschenbach and D. Tim J. Littlewood for the advice regarding the molecular work, Rod A. Bray for the advice regarding parasite identification, the staff of the Wolfson Wellcome Biomedical Laboratories at the Natural History Museum for their technical support, Nicholas Koutsikos for producing the map with the sampling sites' location, and Marcelo Kovacic for curatorial services. For this study, HCMR had secured all necessary permits for fish collection from the Greek Ministry of Environment, Energy and Climate Change (permit numbers 97429/4350 and 85404/130).

Classic (polybromodiphenyl ethers, PBDEs) and emerging halogenated flame retardants (HFRs) such as decabromodiphenyl ethane (DBDPE) and halogenated norbornenes, as well as organophosphate flame retardants (OPFRs) were analysed in 52 sediments and 27 fish samples from three European river basins, namely the Evrotas (Greece), the Adige (Italy) and the Sava (Slovenia, Croatia, Bosnia and Herzegovina and Serbia). This is the first time that FR levels have been reported in these three European river basins. The highest contamination was found in the Adige and Sava rivers, whereas lower values were obtained for the Evrotas. The levels in sediment samples ranged between 0.25 and 34.0 ng/g dw, and between 0.31 and 549 ng/g dw, for HFRs and OPFRs respectively. As regards levels in fish, concentrations ranged between 9.32 and 461 ng/g lw and between 14.4 and 650 ng/g lw, for HFRs and OPFRs, respectively. Thus, whereas OPFR values were higher in sediments, similar concentrations (in the Evrotas) and even lower concentrations than HFRs (Sava) were found for OPFRs in the fish samples, indicating the lower bioaccumulation potential of OPFRs. Biota to sediment accumulation factors (BSAFs) were calculated and higher values were obtained for HFRs compared to those assessed for OPFRs. © 2017 The Author(s) ; This work was funded by the European Union Seventh Framework Programme (FP7/2007-2013) under the Globaqua project (No. 603629), and by the Generalitat de Catalunya (Consolidated Research Groups 2014 SGR 418 -Water and Soil Quality Unit). The authorswould like to thanks Nicoleta A. Suciu (Institute of Agricultural and Environmental Chemistry, Università Cattolica del Sacro Cuore di Piacenza) for her contribution in statistical analysis. ; Peer reviewed