Preliminary study on feeding habits and condition factor of Salmo trutta macrostigma (Dumeril, 1858) in Karasu River

Abstract

The study area, which is in the tributary of Karasu River (Yeşildere, Köşk, Ağasuyu, Sincan, Poik, Çiğdemli, Han, Karahasan, Taşağıl, Karataş, Büyükgöze, Deli, Eriç, Kırık, Karnı streams) in the East Anatolia region of Turkey. The total length and weight of the sampled ranged between 8.6-27.4 cm and 5.4-241 g. Following the removal of digestive tracts, stomachs were opened. Stomach contents flooded with distilled water were examined under a stereoscopic microscope. Contents were sorted and prey items were identified. The number of red spotted trout stomachs that contained at least one prey item or any digested remains was 72 (%69.2). There were 32 (%30.8) empty stomachs. The most important groups were mayfly and simulidae (with IRI=58.6% and IRI= 33.2 % respectively) for Salmo trutta macrostigma in Karasu River. Chrinomid, stonefly, caddisfly, gammarus, unidentified small fishes were the rare in the food groups. The condition factor varied between 0.820-1.621

Keywords

• Condition factor, Karasu River, Red-spotted trout, Salmo trutta macrostigma, Stomach contents

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