Individual growth rate and age at first sexual maturity in Atlantic salmon

• Main Authors: Nævdal, Gunnar, Holm, Marianne, Lerøy, Rita, Møller, Dag
• Format: Report
• Language: English
• Published: 1978
• Subjects: Atlantic salmon
• Online Access: http://hdl.handle.net/11250/114428

Growth rates and possible connection between growth rate and age at maturation were studied on individually tagged salmon originating from different river populations. Great variations in growth rate and in age at first maturity were found among sibgroups of salmon originating from different populations (localities). Although much less pronounced, variations in these traits were also noted among groups within the localitics. When separating the individuals into groups according to age at first maturity, small variations were found within populations for smolt size, size after one summer and size after one year in the sea. The correlation between age at maturation and earlier growth rate thus seems to be rather small. Significant correlations were found between size (length) at different times after the smolt stage both concerning the group means and the individual deviations from the means. Mature fernale grilse stripped for eggs survived at about the same rate as immature fish during the spawning season while the survival rate of male grilse was considerably lower. Weight gain for immature fish during the same period was about two and a half time that of mature females and three times that of mature males.