Analysis of Reproductive Performance of Rainbow Trout in a Hatchery in Chile

Reproductive variables of 986 female rainbow trout (Oncorhynchus mykiss) spawned during 1990 in a hatchery in central Chile were evaluated. Data were recorded on individual females. Fish were spawned over a 9-month period, from March to November. The data indicated the coexistence of different strains of fish with different spawning times. There was a direct relationship between body weight and total fecundity (r = 0.71; P < 0.001, n = 905). The correlation between body weight and egg diameter was low (r = 0.16; P < 0.001; N = 890). The correlation between body weight and relative fecundity was not only low, but slightly negative (r = -0.14; P < 0.001; N = 906). There was a high correlation between fertilization rate and survival of the embryo to the eyed stage (r = 0.75; P < 0.001; N = 903). Embryo survival to the eyed stage appeared to be closely related to incubation temperature, with highest yields obtained during months that average water temperature was 8°C or lower. Egg diameter was not positively correlated with survival to the eyed stage.