Translation Series No.1211

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necessary to follow the growth beyond the sea year class A.1+. Here, how-
,I)ew-c,144s
ever, it is found that the year's-ret of smolt of 1959 as sea year class
À.2+ does no longer show a sPecial size. This phenomenon cari be explained
only by the fact that very many, and especially the laxgeet fish have al-
ready emigrated after a stay in the sea of only two years, in order to
spawn in the fall/winter of 1961. The increase in the Swedish river catches
from 110 t in 1960 to 209 t in 1961 provides a hint for this assumption.
5.4.2:3. The influence of the size of smolt on the growth in the sea
It has' already been mentioned:that the smolt are the larger, the
longer the duiation of the sojourn in fresh water and that these differences
Can.still be observed in the adult fish in the sea. Lindroth (1961a) alao
has investigated this question. He arrived at the result that an influence
of the smolt age on the size of the adult salmon could not be proved as
significant in 13 outof 14 cases. Seen from a certain point Of view, it
.seems to be of value, to examine this question.once more on hand of the
• German material of observations.
With the aid of Table 43 we can ascértain the mean annual in-
crease in the age groups 2.2 and 3.2 (the difference between 2.2+ and 2.1+,
and between -3.2+ and 3.1+) and we obtain values of 20.00 and 20,01 cm.
A rate of growth .that agrees that closely for thé two most important age
groups 2.B and 3.B indicates that differences in the mean lengths that
exist already, remain in existence also in the sea.
An important hint, regarding the question,.whether the size of
the smolt can influence the mean lengths of the sea year classes . , is prov-
ided by the figures of Table 33. When one examines the percentage share of
des
'the age groups in the sea year classes for every year4--8--met of smolt, one