SCALES OF THE SPRING SALMON 31 
SESSIONAL PAPER No. 38a 
In comparing the salmon of the “sea type” with those of the “stream type” 
throughout, the former shows to good advantage. At the end of the first year, it has 
a length 6-6 inches greater than the other, and a somewhat similar superiority is 
maintained throughout. At the end of the second year three is still 6-6 inches differ- 
ence and a difference of over 3 pounds in weight, as the small fish weighs very little 
over a pound while the larger weighs over 4. At the end of the third year the differ- 
ence in length is 52 inches and the difference in weight, 7-5 pounds. At the end 
of the fourth year, the difference in length is 3-1 inches and the difference in weight, 
6:5 pounds. At the time they are caught in June and July, if they are in the fourth: 
year, the average length of the ‘‘sea type” is 31-7 inches, and of the ‘‘ stream type” 
26-3 inches, a difference of 5-4 inches, and a corresponding difference in weight of 
7-5 pounds; if they are caught in their fifth year, there is an average difference in 
length of 3-4 inches, and in weight of 6-5 pounds. As in this collection 65 per cent 
are fish of the “sea type,” it would seem to be a good thing if the remainder should 
be encouraged to behave likewise. Hence, instead of keeping the fry of the spring 
salmon in retaining ponds for a year, and losing thereby many pounds of mature 
fish, it would be much better to give all of them every facility in getting down to the 
salt water and a better supply of food as soon as they can stand the change physio- 
logically. The only offset there is comes from the fact that a larger number of fish 
of the “sea type” than of the “stream type” are mature in the fourth year. The 
latter has one year longer to grow in such cases. As it is scarcely any larger in the 
fifth year than the former is in the fourth, there is no special advantage even here. 
If five years instead of four are taken to produce a certain size of fish, there must be 
n loss of 25 per cent here as well. 
It must be distinctly understood that these remarks apply to the spring salmon 
only, and to the spring salmon as I have found it. It does not necessarily apply to ° 
any other species of Pacific salmon. That quite the opposite is true for the coho is 
shown in another paper being published, and it remains to be seen what is the nature 
of the application in other species. 
SUMMARY. 
The growth of the scale in the spring salmon is a good indication of the growth 
of the fish. Annual bands of growth appear on the scale, each consisting of a wide 
portion with the lines on it somewhat distant, and a narrow portion with the lines 
closer together. The narrow band may be called the “winter check” appropriately, 
because, although the retardation of growth is due to a lack of food rather than to a 
lowering of the temperature, it is produced in the winter months, January, February, 
and March, with indications of it in December and April. 
There are two types of scales, since some of the salmon migrate to the sea as 
fry and have no fresh-water record on their scales, while others migrate as yearlings 
or fingerlings after having a year of comparatively slow growth on the fresh water 
clearly indicated on the scales. 
The majority of both types mature in their fourth or fifth years; probably a 
greater percentage of the ‘‘sea type” than of the “stream type” mature in the fourth 
year, but a majority of the whole number are of the ‘‘sea type.” The fish that mature 
in the fourth year are, as a rule, among the larger of the year-class. Possibly if 
enough third-year grilse were examined there would be proof that they are among the 
largest of the year-class. 
The “sea type” fish has a decided advantage throughout life, both in length and 
in weight, so much so that an average fish of the “stream type”, mature in the fifth 
year, is scarcely larger than a “sea type” fish mature in the fourth year. If they are 
both in the same year when mature, either the fourth or fifth, there is an average 
difference of 6 or 7 pounds. Unless there is some other preponderating reason for 
