Growth rate and age at sexual maturity of Atlantic salmon smoltifying at one and two years of age
Original version
This report is not to be quoted without prior consultation with the General Secretary.Abstract
Postsmolt growth rate and age at first maturation are compared
for sibgroup or population groups of salmon originating from
Norwegian rivers and fish farms. Generally high correlations were
found between corresponding values (lengths at different ages and
proportions of mature fish in the second and third sea year) for
one and two year smolt. One year smolts were smaller at the smolt
stage and grew slower the first sea year, but the two categories
reached practically the same total length after two years in the
sea. In most groups and in the total material one year smolt gave
higher proportions of grilse. Proportions of mature fish during
their third sea year were similar for one and two year smolt of
the same groups. Pronounced variations between sibgroups and
population groups were found both in growth rate and mean age at
first maturation. This variation was much bigger than the variation
between one and two year smolt of the same sib group.