— 143 — 
The average weight of the fish will thus be approximately as follows: 
At 11% years 0.04 kg. 
y Qo » 0.07 » 
» 3 » 027) 
» 4 » 04 » 
» 5 >» ILe » 
» 6 » Io » 
» 7 » 18 » 
» 8 » Be » 
y 9 » oa) » 
» 10 » 40 » 
At two years of age, the weight of the cod is nearly a hectogramme, at three, it is twice 
that figure, and at four years, the weight is about 4 hectogrammes. A five year old fish 
weighs about a kilo, next year one and a half, and at seven years, about 2 kilos. At 
nine years of age the fish weigh three, at 10 years four kilos. All these figures are na- 
turally only approximate, and subject to great variation from one individual to another; 
they serve, however, to give a sufficiently accurate idea of the relation on the whole. 
One variation in the weight of the cod is of great importance, viz, that consequent 
upon spawning. As the genital organs mature, all reserve matter, fat, etc. disappears 
from the whole of the body, being consumed in the formation of the milt and roe. When 
the fish are fully spent, the weight is found to have greatly decreased; after spawning, 
however, the fish again commence to grow fat and heavy. The weight, and the amount 
of fat are at their highest in summer, when the fish have been able to feed liberally on 
the shoals of capelan ete. It is therefore of particular interest to compare the weight 
of the spent skrei (1) with that of Finmark fish (2) of the same size. An exceptionally 
favourable opportunity of so doing occurred in 1913, when the skrei and the Finmark 
fish consisted almost entirely of the same sizes. I therefore give below the average 
weight for the different sizes of skrei and Finmark fish in 1913. 
Average weights (whole) in kilos, of different size groups of skrei and Finmark fish 1913. 
Nr. 65—69 70—74 75—79 80—84 85—89 90—94 95—99 100—104 105—105 
1 Servaagen 23. April 20 22 2.9 34 43 56 6.2 6.8 8.6 
2 Werks Bl, ME socs 2S Sl. G8 467 Si Os TY) 9.8 11.3 
1 Oly OF Boos 87 71 71 75 78 86 78 70 76 
The figures in the last line express the percentages furnished by the spent fish in 
each group of the weight of the fat summer fish. It will be seen that these amount to 
between 70 and 87 %. This is to say, that the spent fish have lost 4, or !/, of their mid- 
summer weight; so great are the fluctuations which may take place in the course of the 
year. 
Weight of gutted cod. 
In dealing with measurements of thousands of fish, it is surprising to note the regular 
proportion between the whole and gutted weights for all size groups in the same sample. As 
