I. Sirakov, Y. Staykov, E. Ivancheva, G. Nikolov, A. Atanasov

Abstract. The relationships among 15 morphometric measurements and carcass weight in European perch (Perca fluviatilis) were examined in connection with sexual dimorphism. The determinated sex ratio was 1:1.3 in the advantage of the male sex. The female perch were larger than male perch by 20,7%, but the carcass weight of the male specimens was by 4,7% better in comparison with the ones measured in female specimens. There were found five morphometric characters that differ between genders: lD1 (1-st dorsal fin lenght) (p≤0.05), lA (anal fin lenght)(p≤0.05), hA (anal fin height) (p≤0.05), lp (pectoral fin lenght) (p≤0.001), lV (ventral fin lenght) (p≤0.05).