Zehra Arzu Becer OZVAROL, Ayhan YILDIRIM, YAŞAR ÖZVAROL

Feeding ecology of various length-classes of brown trout (Salmo trutta) in different streams of Coruh river, Turkey

Bu çalışmada, Çoruh Nehri üzerindeki farklı derelerdeki ve farklı büyüklükteki alabalıklar tarafından tüketilen besinlerdeki değişim incelenmiştir. Ağustos 2008-Temmuz 2009 tarihleri arasında elektroşoker ile avlanan 277 adet alabalık bireyinin besini, her balık başına düşen besin miktarını ve tercih ettikleri omurgasız canlıları belirlemek amacıyla tanımlanmıştır. Aynı zamanda zeminden omurgasız örnekleri de toplanmıştır. Trichoptera, tüm derelerdeki alabalıklar için en bol organizma olmuştur. Alabalıkların besinini, en çok tüketilen takson olarak başta Trichoptera olmak üzere 20 çeşit besin organizması oluşturmuştur. Her boy sınıfındaki balıklar farklı besinleri tüketmişlerdir. En önemli ve en çok tercih edilen besin organizması, değişik boy grubundaki alabalıklar arasında değişim göstermiştir. 3-11.9 cm ve 12-20.9 cm boya sahip alabalıklar başlıca sırasıyla Trichoptera (Limnephilus sp.), Saltatoria (Tetrix sp.) ve Trichoptera (Sericostomata sp.) üzerinde beslenmişlerdir. 21 cm’den büyük alabalıkların besinini ise Ephemeroptera (Epeorus alpicala), Diptera (Simulium sp.) ve Saltatoria (Tetrix sp.) oluşturmuştur. Sonuç olarak bu çalışma, alabalıkların çeşitli besin maddeleri ile beslendiğini, besin ve beslenme davranışının balık büyüklüğüne ve habitata göre değiştiğini göstermiştir.

Anahtar Kelimeler:

nehirler, Salmo trutta, Simulium, Trichoptera, Türkiye, dere alabalığı, diyetler, beslenme davranışı, balık beslenmesi, tatlısu balıkları, habitatlar, akarsular, alabalık

Turkey Çoruh Nehri (Türkiye) üzerinde bulunan farklı derelerdeki çeşitli boy sınıflarına Ait Alabalıkların beslenme ekolojisi

In the present study, It was investigated a variation in food consumption by brown trout Salmo trutta, of diff erent sizes and streams of Coruh river, Turkey. The diet of 277 brown trout individuals were described for the purpose of registering the number and frequency of prey objects per fish, and their selection of invertebrate fauna by electroshock between August 2008 - July 2009. Samples of invertebrate fauna were also gathered from the stream bottom. Trichoptera was the most abundant organism in all streams for brown trout. The diet of brown trout included 20 types of organisms, with Trichoptera as the most consumed taxa. Each length class of fish consumed diff erent prey taxa. The most important and preferable food item varied among the length classes of the brown trout. In the fish 3-11.9 cm and 12-20.9 cm fed chiefl y on Trichoptera (Limnephilus sp.), Saltatoria (Tetrix sp.) and Trichoptera (Sericostomata sp.), respectively. In the fish >21 cm fed on Ephemeroptera (Epeorus alpicala), Diptera (Simulium sp.) and Saltatoria (Tetrix sp.). In conclusion, this study had shown that brown trout fed on a variety of prey items, and the diet and feeding behaviour changes by habitat and fish size.

Keywords:

rivers, Salmo trutta, Simulium, Trichoptera, Turkey, brown trout, diets, feeding behaviour, fish feeding, freshwater fishes, habitats, streams, trout,

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