We studied feeding behavior and prey selection of topmouth gudgeon (Pseudorasbora parva), big-scale sand smelt (Atherina boyeri) and pike-perch (Sander lucioperca) in Lake Eğirdir, the second largest freshwater lake in Turkey. Fish specimens were collected between January and August in 2010 and 2011 using gill-nets and purse seines. A total of 941 specimens were analyzed for stomach contents analysis. We expressed the importance of the food items present in their guts with the relative importance index (IRI) and estimated their diet selectivity indices with Pearre’s index. Pseudorasbora parva had a diverse diet comprising mainly Nitokra hibernica (copepod), Chydorus sphaericus, and Bosmina longirostris (cladoceran) (each, at p < 0.01), but Chironomus sp. (insect) was not a significant component of its diet (p > 0.05). Big-scale sand smelt often preferred B. longirostris, N. hibernica, and Alona quadrangularis (each at p < 0.01). Pike-perch positively, but not statistically significant, selected Atherina boyeri (p > 0.05), Carassius gibelio was not preferred by pike-perch as food item (p > 0.05). Our results indicate that invasive species altered the food chain in Lake Eğirdir. Thus, because these fish species constitute a major threat for native fish species for food and breeding grounds, extensive care should be taken to prevent invasive fish species entering lakes in Turkey.

我们研究了土耳其第二大淡水湖埃格迪尔湖的普斯茅斯udge （Pseudorasbora parva），大型沙渣（Atherina boyeri）和鲈鱼（Sander lucioperca）的摄食行为和猎物选择。在2010年至2011年的1月至8月之间，使用刺网和围网围网收集了鱼类标本。总共对941个标本进行了分析，以进行胃内容物分析。我们用相对重要性指数（IRI）表示了肠道中存在的食物的重要性，并用Pearre指数估算了其饮食选择指数。Pseudorasbora parva的饮食多样化，主要包括Nitokra hibernica（copepod），Chydorus sphaericus和Bosmina longirostris（cladoceran）（每个，p  <0.01），但Chironomus sp。（昆虫）并不是其饮食的重要组成部分（p  > 0.05）。大型砂冶炼厂通常更喜欢B. longirostris，N。hibernica和Alona quadrangularis（每个p  <0.01）。鲈鱼呈阳性，但无统计学显着性，选择了Atherina boyeri（p  > 0.05），Car鱼不喜欢Carassius gibelio作为食物（p > 0.05）。我们的结果表明，入侵物种改变了埃格迪尔湖的食物链。因此，由于这些鱼类对粮食和繁殖地的本地鱼类构成了重大威胁，因此应采取广泛的措施以防止入侵性鱼类进入土耳其的湖泊。