The first occurrence of Carassius gibelio (Bloch, 1782) and Carassius auratus auratus (Linnaeus, 1758) in the Orontes River Basin (Hatay, Turkey) - Page 02

Results and Discussion

In this study, two exotic fish species were found in the from Orontes River Basin; C. a. auratus and C. gibelio. 11 specimens of C. gibelio and 2 specimens of C. a. auratus were collected from the Guzelburc locality in the Orontes River and the Karasu Stream. The study area substrate is muddy with small gravel fractions. The water temperature was 21.5 and 26.1 °C, pH: 8.65 and salinity 0.4 and 0.7 ppt. The water had high turbidity.

 

Fig02
Figure 2: Carassius auratus auratus (Linnaeus, 1758)

 

Fig03
Figure 3: Carassius gibelio (Bloch, 1782)

 

Three males and eight females of C. gibelio and two females of C. a. auratus were caught in the river basin. The total length for males was between 14.0 and 17.9 cm and for females from 15.7 to 20.1 cm in C. gibelio. The total length for females was between 16.0 and 18.4 cm in C. a. auratus.

Goldfish (C. a. auratus) was distinguished from other species of Carassius by: golden-brown, bronze colour, last simple anal and dorsal rays strongly serrated, 26-31 total lateral line scales, free edge of dorsal concave or straight and peritoneum black (Kottelat and Freyhof, 2007).

Prussian carp (C. gibelio) was distinguished from other species of Carassius by: silvery-brown colour, last simple anal and dorsal rays strongly serrated, 29-33 total lateral line scales, free edge of dorsal concave or straight and peritoneum black (Kottelat and Freyhof, 2007).

Fish size ranged from 14.0 to 20.1 cm in total length (TL) and between 11.4 and 17.2 cm in standard length (SL) for C. gibelio and C. a. auratus ranged from 16.0 to 18.4 cm in total length (TL) and from 13.6 to 15.7 cm in standard length (SL).

Exotic freshwater fish species have been introduced in Turkey since the 1930s to promote angling diversity. A total of 26 exotic species have been introduced as eggs, fry or fingerlings for different purposes over the last eighty years (Innal and Erk'akan, 2006; Yalçin-Özdilek, 2007).

The goldfish was reported for the first time by Izci (2004) and was introduced in the early 1990s in Eğirdir Lake. The present distribution of this species in 17 water bodies of Turkey is known so far (Innal, 2011). Nevertheless, the Prussian carp is the most distributed fish species of the genus Carassius in Turkey with up to 77 water bodies invaded (Özcan, 2007; Innal, 2011; Tarkan et al., 2012).

In the last century, four non-native freshwater fishes have become established in the Orontes River Basin, part of Turkey (Yalçın-Özdilek, 2007; Geldiay and Balık, 2007). The present study reports new locality for two species and the number of species of the non-indigenous freshwater fish fauna of the Orontes River Basin (Turkish part) reaches a total of 6.

The introduction of exotic species can reduce diversity of endemic freshwater species living in the Orontes River. The effective control of alien species and public awareness of the introduced species in the future should be aimed at preventing their entry into the basin.

 

Acknowledgements

I would like to thank Dr. Ali S. Tarkan, Muğla University, Turkey for his valuable comments on a draft of this paper.