Reproductive behavior of the rainbow trout Salmo irideus Gibbons (Osteichthyes,Salmonidae) under intensive culture.

Abstract

The purpose of this paper is to study some aspects of the rainbow trout (Salmo irideus) reproduction under intensive culture. The structural characteristics and macroscopic variations of the ovaries were described, and based on these observations a maturity scale of six stages was elaborated. The spawning time and type were determined based on the gonadal maturation curve and in the distribution of the monthly relative frequency of stages. It was observed that the spawning type is total and occurred in June and July when the mean monthly values of the water temperature and the photoperiod reached its lowest values. It was also determined that the females and males reached the first sexual maturation when they were, respectively, 21.7 cm and 20.1 cm long and one year old.