Biological features of the white bream Blicca bjoerkna (Linnaeus, 1758) from Cuciurgan

Abstract

The ichthyocenosis of the Cuciurgan reservoir of the Moldovan Thermal Power Plant is home to the common bream, an eudominant species with a dominance index value (D5) of 53.07 % in catches taken with 25 x 25 mm – 40 x 40 mm mesh gillnets. Currently, the number of white bream is at a stable level with a tendency to remain approximately constant over the next few years. The absolute linear dimensions (L) of the common bream in the Cuciurgan reservoir range from 4.8-31 cm, standard length (l) – from 3.8 to 24.5 cm. Body weight reaches 334 g. The gender structure of the common white bream population in this ecosystem demonstrates the dominance of females in the ratio of 2:1. The reservoir’s white bream is characterized by a high fattening ratio, which according to Clark is 1.96 ± 0.013. A small part of the white bream (1.5 %) in the Cuciurgan reservoir uses fish species as trophic resources.