Abstract: The non-indigenous fish species, Prussian carp Carassius gibelio (Bloch, 1782), was first reported in the Thrace region of Turkey. The species is now established in at least 46 freshwater systems (lake, river, reservoir, lagoon and pond) of Turkey and the species’ spread has been especially rapid between 1998 and 2006. Especially, this species show the rapid invasion of Carassius gibelio in Turkish freshwater systems from Thrace to Anatolia.
INTRODUCTION
The Prussian carp (Carassius gibelio (Bloch, 1782)) inhabits freshwater streams, ponds and lakes and has wide geographic distribution from northern Europe to Asia (Jiang et al., 1983; Abramenko et al., 1998; Kalous et al., 2004). It has spreaded in Russia, Europe, Korea and northeast China (Zou et al., 2001). Over the last five decades, 25 exotic fish have been introduced to the inland waters of Turkey (Innal and Erkakan, 2006). Amongst the most recent invasive introductions (Baran and Ongan, 1988) is that of the Prussian Carp Carassius gibelio (Bloch, 1782). This species is already established in at least 12 European countries and range expansion of the freshwater system of Turkey.
Biological invasions have caused considerable distribution to native ecosystems around the world (Rainbow, 1998; Williamson, 1999; Money and Hobbs, 2000). C. gibelio is known as one of the most hazardous fish species for native fish communities (Crivelli, 1995; Kalous et al., 2004). Also is known as a dangerous species for the native fish communities and its introduction should be prohibited.
Three fish species belonging to Carassius genus occur in the Turkish freshwater systems: Carassius gibelio (Bloch, 1782), Carassius carassius (Linnaeus, 1758) and Carassius auratus (Linnaeus, 1758). Only C. carassius is definitely native to European waters. C. gibelio is might be native to northern Europe (Kottelat, 1997).
It has been reported that C. gibelio was first found in 1988 in Gala Lake of Turkey (Baran and Ongan, 1988). Later on, Prussian carp was found in Thrace Region (TR) (Özuluğ and Meriç, 1996; Özuluğ, 1999; Özuluğ et al., 2004; Özuluğ et a l., 2005a, b; Ilhan et al., 2005; Tarkan et al., 2006) and Asia Minor (AS) (Iznik Lake, Tarkan et al., 2006; Iznik Lake (Van) Özuluğ et al., 2004; Buyuk Menderes River Basin (BMR) (Şaşı and Balık, 2003; Ilhan et al., 2005; Present study), Kızılırmak and Yeşilırmak Basin (KYB) (Ilhan et al., 2005; Yılmaz et al., 2007; Uğurlu and Polat, 2007; Bostancı et al., 2007) and Mediterranean region: Lycia Basin (LB) (Çildir, 2001; Balık et al., 2004; Balık et al., 2007; Ilhan et al., 2005; Balık et al., 2003; Bostancı et al., 2007) and Cilicia Basin (CB) (Alagöz et al., 2006)) (Thrace Region (TR), Asia minor (AS), Buyuk Menderes river basin (BMR), Kızılırmak and Yeşilırmak Basin (KYB), Mediterranean region: Lycia Basin (LB) and Cilicia Basin (CB)) (Fig. 1).
The objectives of the present study to report the occurrence of the species in a new locality in the Asia minor and recent distribution of the freshwater system of Turkey. The documentation of the exotic species is important in order to track their dispersal and appraise threats to native species (endemic), endangered species and ecosystems.
MATERIALS AND METHODS
Eleven specimen of C. gibelio (Bloch 1782), was collected in Kemer Reservoir and Akçay Stream system (Aegean region), Turkey, (between 37°32' 58" N and 28° 32' 48" E) on 19 May 2006. The other data (except for Kemer reservoir and Akçay catchment) related to distribution of Prussian carp based on literature. Sampling was performed by using gill nets (18-45 mm mesh sizes) and cast nets (12-22 mm mesh sizes). The specimen was preserved in 4% formaldehyde and deposited at the Faculty of Fisheries, Mustafa Kemal University, Turkey (in collection of Dr. G. Özcan).
The water level of the reservoir decreases every year in the late spring and summer because of irrigational use. When the rainfalls begin winter, the water level increases again. The surface of Kemer Reservoir is 14.75 km2, the size of overall volume totals 544 hm3. According to the measurements taken in 2004-2006, the maximum depth measured was 51 m. It has 1 outlet, Akçay Stream system and 6 inlets, Değirmen, Deli, Akdere, Sarhos, Yeni and Mortuma streams.
RESULTS AND DISCUSSION
The Prussian carp have been reported 46 freshwater systems of Turkish (12 lake, 11 reservoir, 14 river and stream, 6 pond, 3 lagoon) so far (Fig. 1). This is the report in two new localities of Prussian Carp in the Asia Minor (Kemer reservoir and Akçay catchment). The population in Kemer Reservoir appears to be reproducing successfully, as large numbers were observed. Besides, it has been utilized economically by the fishermen of the region and sold as such a carp caught in Marmara Lake (Manisa) whose population is intense (Table 1).
Cohabitation with this species, pumpkinseed, Lepomis gibbosus (Linnaeus, 1758), the negative outcomes of the food competition in which it attempts to compete with economic native species in the sources where it is introduced (Şaşı, 2002; Özcan, 2007). It has been identified as responsible for impacts on native species (Balik et al., 2004; Vetemaa et al., 2005).
After reporting in Topçam reservoir, it spreaded quickly in Anatolia in a very short period of three years. After observing this species in Akçay Stream system which is an important water course in especially Menderes River basin and Kemer reservoir found on it, the area of spread is seen to have expanded. And this shows that the spreading area of exotic species is expanding in Anatolia gradually. It is pointed out by Smith and Darwall (2006) that Menderes river basin is a basin in which important endemic freshwater species of Europe are found and a basin where two or three species are in danger. Many native species do not tolerate cohabitation with the alien species. The expanding population and improving of this species show that the endemic species living in this basin are under threat. Its introduced range is expanding rapidly and for this reason it is important to monitor the dispersal and to assess the impacts of this introduced species on endangered endemic species and natural ecosystems.
As a result, due to the fact that this species, with L. gibbosus, is found in Menderes river basin and that there are endemic fishes reported to be under a serious threat by IUCN in 2006, these endemic fish species are in a serious danger.
| Fig. 1: | Map of the study area
1. Ilhan et al., 2005; 2. Baran and Ongan, 1988; 3. Balık
et al., 2004; 4. Bostancı et al., 2007; 5. Balık
et al., 2007; 6. Yılmaz et al., 2007; 7. Uğurlu and
Polat, 2007; 8. Balık et al., 2003; 9. Tarkan et al.,
2006; 10. Özuluğ et al., 2004; 11. Şaşı
and Balık, 2003; 12. Özuluğ, 1999; 13. Özuluğ and
Meriç 1996; 14. Alagöz et al., 2006; 15. Present study |
| Table 1: | Records of Carassius gibelio in the inland water of Turkey in 1982-2007 |
We need a better international coordination structures to develop a cooperative strategy for the protection of native species against invasive alien species and it is important to prevent the further spread of invasive.