Translation Series No.1211

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discharging gonads were caught during the months November to February in
the Daltic Sea. Mature males are also found occasionally. Nordgaard (ac-
cording to Nereheimer 1941) also has demonstrated that salmon can mature
in the sea. Fertilization and development of the eggs, however, is not pos-
sible, because all the necessary conditions for this are lacking in the
ocean.
The development of the gonads in the rising mature salmon, the
act of spamning, the Conditions for fertilization and the embryonal dev-
elopment have in pari investigated very thoroughly. There are, however, no state-
menté about the sexual circumstances during the maritime stage.
3.1. The sexhal composition of the exploited stock
If we assume.that the newly hatched brood consists of equal
numbers of males and females, then among the migrating smolt, the females
must be in the majority, because some males always remain in the rivers.
During the 'second year in the sea, the numerical proportion among the -sexes
LP.26 2] •
continues to shift in favour of the females, because already more males
(eilse) than females have migrated to the spawning grounds. The investig-
ation of the salmon catches at sea should therefore yield more females than
males.
In this connection we shall examine the composition in regard
to length and sex of eight salmon catches of 997 fish from the-years 195 8 .
and 1959 (Fig. 12). The sexual figure 6 amounted collectiveiy to 0.391.
Thé value for the fishing ground 6 (Bornholm) was 0.438, that for the .
fishing ground 5 in contrast only . 0.371. The differenoes between the two
fishing grounds are, however, notiignificant, since the value 0.438 is
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6 After A. BUckmann (1929). The decimal fraction that indigates the proportion
of males is called the Sexual figure.