Reproductive behavior of male rainbow trout (Oncorhynchus mykiss) during reproductive period

Abstract

In this study it was described and characterized the reproductive behavior of male rainbow trout during reproductive period. Results indicate that reproductive period is in the months of August until February. Semen production variated at population level, 60% of population presented higher production in September 33.59 ± 13.69 mL, 30% in October 28.76 ± 10.22 mL and 10% in November 75.53 mL. Statistical analysis detected significant differences between the months (P<0.05) and at individual level (P<0.05). Spermatozoids concentration mL^-1 variated at individual and population level. Spermatic concentration in 70% of population decreased as reproductive period progressed. August and September where the months with highest concentrations of spermatozoids mL^-17.71 ± 2.85, 7.76 ± 1.85 x 10⁹ respectively. Statistical analysis detected significate differences between months (P< 0.05). Seminal pH was alkaline with light variations at individual and population level. Statistical analysis did not detected significant differences between months nor individual months (P< 0.05). This confirms that there is a variation in seminal quality of the same organism. Which is interesting for selection of best breeders, decrease maintenance costs and also reduce number of males.