ALASKA FISHERY AND FUR-SEAL INDUSTRIES, 1920. 131 
extent the early cohos turn into the Tanana it was impossible to 
determine. 
In the lower two or three hundred miles of the river the cohos 
during the early days of August may maintain the bright silvery 
coloration with which they enter from salt water, but soon a pinkish 
tinge appears, which becomes intensified to a bright red before Ruby 
is reached. At the same time the upper jaw of the male becomes 
bluntly hooked over the lower jaw, producing the characteristic snub- 
nosed appearance of this species on the spawning grounds, and the 
enlarged teeth of the males are soon in evidence. These changes in 
appearance may have already occurred before entering the river in 
the case of the latest individuals to enter. 
It is most unfortunate that the only name by which the coho salmon 
is commonly known on the Yukon is “ chinook,” which is the special 
name of the king salmon of the Columbia River and is totally inap- 
plicable to the coho. Near the mouth of the Yukon, where the influ- 
ence of the cannery has been felt, the coho is generally and properly 
designated as the silver salmon, which is one of the two names by 
which the species is known in other fishing centers of Alaska. Unfor- 
tunately, as will later appear, elsewhere throughout the Yukon 
the term “silver salmon” is generally but mistakenly applied to 
an entirely different species. To avoid confusion, therefore, it is 
suggested that this species be known on the Yukon as the coho, a 
name by which it is generally known to the trade. 
KING SALMON, 
The king salmon appears at the river mouth shortly after the ice 
has run out—in the last week of May or the early days of June. The 
numbers rapidly increase, the run culminates quickly, and then 
almost as quickly declines. During the season of 1920 the first king 
salmon was obtained on June 13, although nets had been set to test 
the grounds for five days prior to that date. The rapidity with 
which the run sets in is well shown by the records of the first few 
days at the cannery. On June 15, 34 king salmon were obtained; 
on June 16, 175; June 17, 1,639; and on June 18, 5,228, this being 
the next to the largest take on any day during the season. The 
largest capture of king salmon in any one day was 6,104 on June 21. 
In no other day, except the two above mentioned, did the number 
captured quite reach 4,000. The run may be said to have begun on 
June 15 and to have culminated within the first week. It continued 
for some 10 days thereafter at a high level, and then registered un- 
mistakable decline. The average take at the cannery for the best 
consecutive 16 days of the run was a little more than 3,000 fish 
per day. 
The experience during the previous season, 1919, was very similar 
as regards the beginning, culmination, and decline of the king salmon 
run. The fish appeared during the second week in June, ran most 
abundantly during the following week, continued at a high level 
for two weeks more, and then rapidly fell off. 
The average size of the 1920 king salmon was greater than that 
of 1919, as is shown by the average number required to make a case 
in each of the two years. The average number in 1919 was 3.54 to 
the case, while in 1920 it required but 3,03. The difference was even 
