Non-native fish species in Slovak waters: origins and present status

Abstract

Abstract:Freshwater fishes recorded in the territory of Slovakia include 95 fish species. As many as one third of these are allochthonous fish species belonging to 14 families, among which several have not occurred in Slovakia recently. Historically, there were three main periods of introduction: the first is the beginning of the 20 th century, the second includes two decades between 1955 and 1975 and the third period is from the year 1990 up to the present time. The origins of the exotic species seen in Slovakia are the four continents -Africa (3), North America (7), Central America (3), and Asia (13) and ten of them are from different regions in Europe. The purpose of intentional introductions of non-native species was to occupy vacant ecological niches in the ecosystems reshaped by human activities, fish stocking, angling or fish farming. Some of these species spread from their original ranges or they penetrated spontaneously from the adjacent countries via the river network system. At the present time, 76 fish species in total form populations in Slovakia. There are 54 autochthonous and 22 allochthonous species, 14 of them are exotic fishes. The invasive characters in 13 fish species were considered, the recent native/total fish ratio is 0.71.

The parasites of the invasive Chinese sleeperPerccottus glenii(Fam. Odontobutidae), with the first report ofNippotaenia mogurndaein Ukraine

“…vectors of the fish's introduction. The Chinese sleeper population in the Western Ukraine was a source of this fish invasion in the Danube basin in Slovakia, then in other Danube countries (Koščo et al, 2010;Kvach, 2012). The presence of this parasite in Western Ukraine (current data) and in Slovak waters (Košuthová, 2004;Košuthová et al, 2008Košuthová et al, , 2009Oros and Hanzelová, 2009), as well as its absence in Southern Ukraine, show the vector of the fish invasion.…”

Do non‐native fish as prey favour the conservation of the threatened indigenous Eurasian otter?

“…Dietary breadth (B) ranged between 0.15 and 0.56 (mean = 0.26 ± 0.01; Table 3) for seven food categories (R) and between 0.016 and 0.206 (mean = 0.078 ± 0.038) for Table 2 History of fish introductions for ten European countries (n = cumulative number of naturalised fish for each time period; %I = percentage increase between successive periods): Albania (Shumka et al, 2008), Czech Republic (Lusk et al, 2010), England (Copp et al, 2005a, Copp andFox, 2007;Zięba et al, 2010a,b), Greece (Zenetos et al, 2009), Italy (Bianco & Ketmaier, 2001), Norway (Hesthagen & Sandlund, 2007), Poland (Grabowska et al, 2010), Serbia (Lenhardt et al, 2012), Slovakia (Koščo et al, 2010) 73 categories. RFR analysis suggested there was no significant association, in terms of percentage of explained variance, between any dietary breadth index (R = 7 and R = 73) and either the %RF of non-native fishes in otter diet or latitude (a ranging between 0.371 and 0.771).…”

Global patterns and clines in the growth of common carp Cyprinus carpio

“…carpio represents an important resource for local fisheries, even though in some areas of the species' native distribution interest has also been revolving around its conservation status (Xu et al ., ; Uchii et al ., ). Finally, the relatively large number of studies from the Czech Republic (21 waterbodies) is a result of the relevance of this native and iconic species (now severely threatened or locally extinct in its wild form: Koščo & Holčík, ; Koščo et al ., ) for local fisheries and angling (Balon, ), especially as a traditional dish on Christmas Eve (Britton & Gozlan, ).…”