The diet survey of Perca fluviatilis of Arnirkelayeh lagoon was carried out during four seasons of 2001. After collecting the fish samples by different fishing gear such as gillnet, seine, castnet and dipnet, fishes were measured and diet was studied. Also according to this research from 143 specimen, fishes were in the age range of 1+- 6+, total length of 9.5-33.5 cm (T.L= 19.83±4.46 cm) and weight of 10.5 - 350 g (Mean weight of 114.45±77.55g). According to obtained results, the relative lenght gut was 0.58±0.09, index of fullness was 129.5±257.4, fullton's condition factor was 1320.7±534.1 and vacuity index was 7.69%. Perca jluviatilis was fed from 18 kinds of food with respect of frequency were: water bug, Odonata, Gammarus, plant materials, Chironomids, Tinca tinca, Hemiptera, Perca fluviatilis, Snail, Syngnathus abaster, Gambusia holbrooki, Pungitius platygaster, diptera, branchiopoda, trichoptera, tubifex, frog and shrimp. By consideration of composition eaten foods and their frequency percentage in Amirkelayeh lagoon Perca fluviatilis, it can be concluded that this fish is an omnivorous and cannibalism species. Also, feeding habit of Perca fluviatilis changes according to age, season and sex.
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