SIZE STRUCTURE, LENGTH-WEIGHT RELATIONSHIP AND CONDITION FACTOR OF THE BLACK SEA ROACH (RUTILUS FRISII NORDMANN, 1840) IN THE RIVERS VELEKA AND REZOVSKA, BULGARIA
DESISLAVA ROZDINA1, GALERIDA RAIKOVA1, RADOSLAVA BEKOVA2, MARTIN ILIEV3
1 Faculty of Biology, Sofia University “St. Kliment Ohridski”, Sofia, Bulgaria
2 Institute of Oceanology, Bulgarian Academy of Science, Varna, Bulgaria
3 National Center of Infectious and Parasitic Diseases, Sofia, Bulgaria
*Corresponding author: e-mail: d_rozdina@abv.bg
Keywords: size structure, condition factor, L-W relationship, Rutilus frisii, Veleka River, Rezovska River
Abstract: The size structure and length-weight relationship of Rutilus frisii (Nordmann, 1840) in the Rivers Veleka and Rezovska, Bulgaria were studied. The smallest individual caught in Veleka River was with length of 6.6 cm and weight of 5.2 g. The largest individual was with length of 15.5 cm and weight of 57.4 g. The smallest individual caught in Rezovska River was with length of 10.3 cm and weight of 18.8 g and the largest one was 13.2 cm in length and 31.5 g in weight. In the both rivers the most abundant was the size class 10.1-11 with 24 individuals in Veleka River and 12 individuals in Rezovska River. The L-W relationship for the catches from Veleka River was W = 0,017L2,9664, R² = 0,9805. The L-W relationship for the catches from Rezovska River was W = 0,1624L2,0152, R² = 0,8432. The condition factor for the fish from Veleka River was calculated as 1.7 and for Rezovska River 1.5.