Biologia 65/6: 1057—1063, 2010 Section Zoology DOI: 10.2478/s11756-010-0114-7 Non-native fish species in Slovak waters: origins and present status Ján Koščo1,LenkaKošuthová2 , Peter Košuth2 & Ladislav Pekárik3 1Faculty of Human and Natural Sciences, University of Prešov, 17. novembra 1,SK-08116 Prešov, Slovakia; e-mail: [email protected] 2Institute of Breeding and Diseases of Game and Fish, University of Veterinary Medicine and Pharmacy, Komenského 73, SK-04181 Košice, Slovakia 3Institute of Zoology, Slovak Academy of Sciences, Dúbravská cesta 9,SK-84506 Bratislava, Slovakia 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 20th 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. Key words: introduced fishes; Danube; Tisa; Dunajec; biological invasion Introduction Material and methods In the case of absence of a national monitoring network on Both, destruction of natural habitats and introduc- introduced fish species, the data used in this study origi- tions of alien species, led to the changes in biodiver- nated from various sources. sity noted during the last century. Aquatic ecosys- The status of the species was established from histori- tems disturbed by human activities seem to be par- cal research and actual fish sampling. The ratio of the num- ticularly vulnerable to these invasions (Alimov 1998; ber of native species to the total number of species cur- Dgebuadze & Skoromokhov 2002; Moyle & Light 1996; rently recorded (called the „zoogeographic integrity coeffi- Panov et al. 1999; Welcomme 1991). Among the ver- cient“) by Bianco (1990) was calculated. The terms “non- tebrates, introductions of freshwater fish species have indigenous” and “non-native”, “alien” or “exotic” according to Copp et al. (2005) and ecological groups of fishes follow- been the most numerous (Cowx 1997; Gido & Brown ing Holčík (1998) are used. Only species able to overwinter 1999). Introductions of exotic freshwater fishes are one were taken into account. of the main threats to native fish species around the The nomenclature and taxonomical status of fish world. species used follow the papers by Boguckaja & Naseka Many exotic fish species have been introduced to (2004), Kottelat & Freyhof (2007) and Neilson & Stepien Europe, and many more have been translocated among (2009). European countries (Holčík 1991; Lehtonen 2002; Copp et al. 2005). In Slovakia, only preliminary and incom- Results and discussion plete lists of non-native fishes are available (Hensel & Mužík 2001; Kováč et al. 2007) and only a few stud- The introduction of species and their transfer in Slo- ies on interactions between exotic and native fishes vakia have been performed (Žitňan 1974; Lusk et al. 2004; The history of introductions and transfers of alien Košuthová et al. 2008). The aim of the present study species to Slovak waters can be divided into three was to collect, as far as possible, all existing informa- main periods. Except for Rhodeus amarus (Bloch, tion on alien fish in Slovakia by using published data, 1782) and Proterorhinus marmoratus (Pallas, 1814) data from fish farms, fish research institutions, admin- syn. Protherorhinus semilunaris (Heckel, 1837) that istrations and consultants. probably spread via the Danube River hundreds of c 2010 Institute of Zoology, Slovak Academy of Sciences 1058 J. Koščo et al. Table 1. Origin of the non-native species in the ichthyofauna of Slovakia. Family Species First report Original area Origin Present status I Polyodontidae 1 Polyodon spathula (Walbaum, 1792) 1992 North America IF 1R II Acipenseridae 2 Acipenser baerii Brandt, 1869 2006 Asia IF 1R III Cyprinidae 3 Carassius auratus (L., 1758), ca.1900 Asia AR I 4 Carassius gibelio (Bloch, 1782) 1961 Asia S I 5 Cyprinus rubrofuscus Lacep`ede, 1803 1996 Asia S ? 6 Ctenopharyngodon idella (Valenciennes, 1844) 1961 Far East IFAS S, AR 7 Pseudorasbora parva (Temminck et Schlegel, 1846) 1974 Far East S I 8 Hypophthalmichthys molitrix (Valenciennes, 1844) 1965 Far East IFAS S, AR 9 Hypophthalmichthys nobilis (Richardson, 1845) 1964 Far East IFAS S, AR 10 Rhodeus amarus (Bloch, 1782) ca. 1200 Asia S WS IV Ictaluridae 10 Ameiurus melas (Rafinesque, 1820) 1999 North America S I 11 Ameiurus nebulosus (Lesueur, 1819) 1926 North America S I V Clariidae 12 Clarias gariepinus (Burchell, 1822) 1989 Africa IF E VI Coregonidae 13 Coregonus albula (L., 1758) 1957 North Europe IVEN E 14 Coregonus migratorius (Georgi, 1775) 1960 Asia IVEN E 15 Coregonus maraena (Bloch, 1779) 1929 North Europe IVEN O 16 Coregonus peled (Gmelin, 1789) 1970 Russia IVEN E 17 Coregonus wartmanni (Bloch, 1784) 1955 Russia IVEN E 18 Coregonus renke (Schrank, 1783) 1992 North Europe AE 1R VII Salmonidae 19 Oncorhynchus mykiss (Walbaum, 1792) ca. 1900 North America IFAS S, O 20 Salvelinus fontinalis (Mitchill, 1814) ca. 1900 North America IFAS S, AR VIII Thymallidae 21 Thymallus baicalensis Dybowski, 1874 1959 Asia IVEN E IX Cyprinodontidae 22 Poecilia reticulata Peters, 1859 1970 Central America AR O 23 Poecilia sphaenops (Valenciennes, 1846) 1970 Central America AR E? 24 Xiphophorus helleri Heckel, 1848 1970 Central America AR E? XGasterosteidae 25 Gasterosteus aculeatus (L., 1758) 1967 Holarctic Region S I XI Centrarchidae 26 Lepomis gibbosus (L., 1758), 1956 North America S I 27 Micropterus salmoides (Lacep`ede, 1802) 1957 North America AE 1R XII Cichlidae 28 Haplochromis niloticus Greenwood, 1960 1995 Africa IF E 29 Oreochromis mossambicus (L., 1758) 2003 Africa AR O XIII Odontobutidae 30 Perccottus glenii Dybowski, 1877 1998 Far East S I XIV Gobiidae 31 Apollonia fluviatilis (Pallas, 1814) 2001 Danube delta S I 32 Apollonia melanostoma (Pallas, 1814) 2003 Danube delta S I 33 Babka gymnotrachelus (Kessler, 1857) 1999 Danube delta S I 34 Ponticola kessleri (G¨unther, 1861) 1996 Danube delta S I 35 Proterorhinus semilunaris (Heckel,1837) ca. 1870 Danube delta S I Explanations: IF – intentional import (farming), S – spontaneous expansion, IFAS –intentional import (farming, angling, stocking), AE – accidental (escape), AR – aquarists’ release, IVEN – imported to fill the vacant ecological niche. Present status: 1R – one record, I – invasive, O – one population, E – extinct, S – stocked, AR – artificial reproduction, WS – wide spread. years ago (Harka & Bíró 2007; Van Damme et al. Coregonus albula (L., 1758), Coregonus migratorius 2007), the first introductions occurred in the beginning (Georgi, 1775), Coregonus peled (Gmelin, 1789) (Kirka of the 20th century, when Oncorhynchus mykiss (Wal- & Bastl 1963; Holčík 1998), three herbivorous species baum, 1792) and Salvelinus fontinalis (Mitchill, 1814) Ctenopharyngodon idella (Valenciennes, 1844), Hy- followed by Coregonus maraena (Bloch, 1779) a few pophthalmichthys molitrix (Valenciennes, 1844), Hy- years later (Table 1) were imported (Holčík 1969; Volf pophthalmichthys nobilis (Richardson, 1845) (Kokorďák & Hubáček 1930). In the same period Ameiurus neb- 1969; Holčík & Pár 1970) and Thymallus baicalensis ulosus (Lesueur, 1819) penetrated from neighbouring Dybowski, 1874 were introduced (Pavlík 1963). Other countries (mainly Hungary) (Balon 1966). species such as, Lepomis gibbosus (L., 1758) (Balon In the second period (1955–1975), four species & Mišík 1956), Carassius auratus (L., 1758), Caras- of whitefishes Coregonus wartmanni (Bloch, 1784), sius gibelio (Bloch, 1782) (Balon 1962), Gasterosteus Non-native fishes of Slovakia 1059 aculeatus (L., 1758) (Balon 1967) and Pseudorasbora or 13th century (Kottelat & Freyhof 2007; Van Damme parva (Temminck & Schlegel, 1846) (Žitňan & Holčík et al. 2007). 1975) spread spontaneously from adjacent countries. At the end of the 19th and beginning of the 20th The occurrence of Micropterus salmoides (Lacep`ede, century, European angling and fishery organisations in- 1802) – only one specimen (Mišík 1958) and Coregonus troduced several species mainly from North America renke (Schrank, 1783) – four specimens was accidental (Oncorhynchus mykiss, Salvelinus fontinalis, Ameiurus (Holčík 2003), and the distribution area of three or- melas, Ameiurus nebulosus, Micropterus salmoides,and namental species Poecilia reticulata Peters, 1859, Poe- later Polyodon spathula). Some of these species were cilia sphaenops (Valenciennes, 1846), Xiphophorus hel- also introduced to Slovakia (Oncorhynchus mykiss, leri Heckel, 1848 was limited to the thermal brook near Salvelinus fontinalis, Polyodon spathula). Other species the spa in Bojnice town (Hensel