**Author details**

food for large fish. *M. leuckarti* was found to be markedly dominant in stomach content of *P.parva* in May. Indeed, *M. leuckarti* showed spread across the temperate zone of the lake in April–June [61]. In addition, Demirhindi [62] and Aksoylar and Ertan [63] reported variation in distribution of *M. leuckarti* in the lake [43]. The rate recorded in the stomach contents showed that *M. leuckarti* changed by sampling sites. *Pseudorasbora parva* fed on harpacticoid

The results also indicate that topmouth gudgeon feeds on zoobenthic organisms in the lake. Prey selection showed that *D. cucullata, B. lon*girostris, Annelida, Tricoptera larvae and *Gomphonema* sp. positively selected by topmouth gudgeon in Lake Eğirdir; therefore, their selection indices were statistically significant (p < 0.01). Pearre's selectivity indices showed that *A. guttata, C. rectangula, Chironomu*s sp., *C. curvispinum, G. testunidaria, M. leuckarti* and Nauplii were neutrally selected. According to Didenko and Kruzhylina [10], Ivlev's selectivity indices demonstrate that topmouth gudgeon positively selected zooplankters such as *Chydorus sphaericus*, *Alona affinis*, *Pleuroxus* sp. and *Cyclops* sp., but avoided *Bosmina* sp. *Asplanchna priodonta* was also positively selected among rotifers. Anatolian endemics *Aphanius anatoliae* was consumed with a rate of 63.91% in the Lake [64]. In this study, the diatom (from Bacillariophyta) Gomphonema sp. according to the selectivity index, diets low statistically significant (V = 0.225, p < 0.01). Ekmekçi and Kırankaya [17] concluded that *P. parva* develops dense populations in some water bodies and it is blamed for food competition with other species. Moreover, the impact of *P. parva* on natural food structure was shown in terms of zooplankton and zoobenthos and main fish production parameters [65]. Musil et al. [65] found that differences in mean zooplankton members and especially in *Daphnia* density between the seasons of 2003 and 2004 were highly significant in fish ponds (three different ponds). Tarkan [66] informed that the disease vectors, such as *P. parva,* damaging fishing capacity are too large. The topmouth gudgeon has a high reproductive potential and it was uncontrollably introduced into the water resources. In addition, topmouth gudgeon is evaluated in the status

The observations in this study confirm that *P. parva* has diverse diet preferences. Therefore, the topmouth gudgeon should be considered a serious threat to the diversity of food chain in Lake Egirdir since the fish consumes all kinds of organisms in the chain. In addition, it has a potential to carry a variety of diseases. It also be noted that the fish have abilities to produce eggs in large diameters and grow rapidly in a dense population size in a short time. Sexual dimorphism and nest protection behavior are the other advantages of the fish to become a dominant fish population in the lake. Our study is expected to contribute to better knowledge of diet composition of topmouth gudgeon in Lake Eğirdir for future researches. We hope that future researchers can estimate the possible damages on the biomass and species composition of zooplankton in relation to their considerable consumption by the increasing population of *P. parva* in the lake. Finally, it is important to point out that invasive non-native fish species

copepods *N. hibernica* mainly in May.

370 Selected Studies in Biodiversity

of pest species [26].

**5. Conclusions**

Meral Apaydin Yağci1 \*, Ahmet Alp2 , Abdulkadir Yağci1 , Vedat Yeğen1 and Mehmet Ali Turan Koçer3

\*Address all correspondence to: meralyagci@gmail.com

1 Fisheries Research Institute, Republic of Turkey Ministry of Food, Agriculture and Livestock, Eğirdir, Isparta, Turkey

2 Department of Fisheries, Faculty of Agriculture, University of Kahramanmaraş Sütçü Imam, Kahramanmaraş, Turkey

3 Mediterranean Fisheries Research, Production and Training Institute, Antalya, Turkey
