АНАЛИЗ НЕКОТОРЫХ МОРФОМЕТРИЧЕСКИХ И БИОЛОГИЧЕСКИХ ПОКАЗАТЕЛЕЙ ПЛОТВЫ RUTILUSRUTILUS (LINNAEUS, 1758)

Abstract

The common roach is a widespread and semi-anadromous fish inhabiting the waters of Europe, Siberia, the Aral Sea basin. Control catches contained roach with a commercial length 12.6-32.6 cm, with a total mass of 41-543 g, age varying within 1+ - 6+. Juvenile stage individuals made - 5.7%, females - 68.6%, males - 25.7%. The annual gain at the age 1+ - 2+ made 3.8 cm, from 2+ to 3+ = 0.6 cm, from 3+ to 4+ = 2.3 cm, from 4+ to 5+ = 2.5 cm, 5+ - 6+ = 2.3 cm. The rate of linear gain decreases from 2+ and equals 3.2%, from 3+ to 4+ = 11.8%, from 4+ to 5+ = 11.5%, from 5+ to 6 + = 9.5%. The annual gain in body weight of species aged from 1+ to 2+ was 50.8 g, from 3+ was 24.8 g, from 4+ = 79.5 g, from 5+ and 6 + = 112.2 and 23.3 g, respectively. From 2+ to 3+ the weight gain is 17.3%, compared to individuals from 1+ to 2+ (85.1%). In the age categories from 3+ to 4+ and 4+ to 5 +, the weight gain was 47.2% and 45.3%, from 5+ to 6+ = 6.5%. In this study, the roach was prevalent in the II and V stages of gonad maturity. Individuals with I and II degrees of fat content were found in all age groups. The study of roach muscles using the compression method revealed the invasion by Opisthorchis felineus (Rivolta, 1884) and Metorchis bilis (Braun, 1790). Invasion extensiveness of O pisthorchis felineus was 28.6%, of Metorchis bilis - 5.7%, combined infestation with two parasites - 2.8%. Invasion activity in opisthorchis was 15.1 specimens, in metorchis - 5.3 specimens, copiousness index made 4.7 and 0.5 copies, respectively.