Prerequisites for the selection of two-year-old rainbow, trout females by the timing and multiplicity of maturation, when grown in a closed water supply installation

Abstract

The article presents the results of the evaluation of two-years-old female rainbow trout, matured at the beginning, middle and the end of spawning season, by body weight, reproductive characteristics, embryo survival and the frequency of occurrence of fish with bicycle maturation. Significant differences in the mass of eggs were revealed depending on the timing of ovulation. The survival rate of embryos did not depend on the weight of eggs and had high rates in fish that matured in the middle and end of spawning. The frequency of occurrence of bicyclic females among groups of two-year-olds who matured at different times had great differences. The data obtained are important when conducting breeding in order to shift the spawning season and create new layering and trout breeds when breeding in RAS.