Page:The Pacific Monthly volumes 1-3.djvu/86

 the marked fish captured this year (nearly 400 in number) were taken before the 1st of August.

A few days before it is ready to spawn the female hollows out a small nest in the gravel in the bed of the stream, and here the eggs and milt are deposited. The eggs drift into the crevices of the gravel and remain in that protected position during incubation; here also the young remain until the umbilical sac is absorbed. The eggs hatch in from 45 to 60 days, according to the temperature of the water, and the umbilical sac is absorbed in about six weeks thereafter; it will make its home in fresh water for about 10 months, and then go to the ocean, where it remains for two years, when the development of the reproductive organs causes it to seek fresh water in which to spawn, and in all probability it will return to its native river. Absolutely nothing is known of the habits of salmon after they leave fresh water as yearlings; how far they wander from the mouth of the parent stream and what they feed upon is a matter of conjecture, and until the past year the time they re- main in the ocean, after leaving the river, before returning to spawn, was purely a guess, no scientific experiment prior to that having ever been made with a view of accurately determining this important question.

With a view of ascertaining, if possible, the age at which a Chinook salmon returned to spawn, the writer requested Mr. Hubbard, the superintendent of the United States hatchery on the Clackamas, to mark a number of Chinook fry. This he did by cutting off the adipose fin of 5,000 of them. This marking was done in May, 1896, and the fry were held for about 10 days to note the result of the amputation, which did not seem to affect them in the least, and they were released. On the 23d of May of the present year the first of these marked fish was captured and sent to the writer, and between that date and the 1st of August nearly 400 were reported, varying in size from 10 to 57 pounds in weight, and averaging at least 25 pounds. I think this experiment has clearly demonstrated that the ocean life of the Chinook is less than two years. It is believed by many observers that the Chinook while in the ocean feed upon the smelt and sardines that usually run in the Columbia. This theory is based upon the fact that the stomachs of Chinook salmon taken just as they were entering the river have occasionally been found to contain these fish. The return of the marked fish is corroborative of the theory that salmon return to their native waters to spawn.

I receive many letters from persons who are unable to distinguish the young of the salmon from the various forms or species of trout found in the waters of this state. This is a matter easily determined. Any one who will take the trouble to learn which is the anal fin, the one on the lower side nearest the caudal fin, can distinguish young salmon from any species of trout. All the species of Oncorhynchus have from 14 to 20 rays or ribs in this fin, exclusive of the stubs or rudiments in front of the first ray. None of the various species of trout in the waters of this state have more than 11 rays or ribs in this fin. The Chinook or quinnat (Oncorhynchus tschawytscha) in the Columbia has an average weight of 25 pounds, but individuals have been found occasionally that weighed as much as 85 pounds. David Starr Jordan says that they are occasionally taken weighing 100 pounds. My experience and observation leads me to believe that 85 pounds is the maximum weight of the royal Chinook; 60 and 65-pound individuals are quite common. One of the marked fish heretofore referred to was taken by the Pillar Rock Packing Company on the 13th of July, 1898, which was only two years, seven and one-half months old and weighed 57 pounds. The smallest of the marked fish taken weighed only 10 pounds, while the rest varied from 20 to 40 pounds. This demonstrates positively that there is great variability in the weight and size of this species at the same age, and therefore disproves the theory advanced by some that the great variability in size of individuals is caused by the difference in age.

The blueback salmon (Oncorhynchus nerka) is next to the Chinook the most important and valuable of the five species for canning purposes. Taking the entire coast, it is probably more numerous than all the other species combined. It is known on the different coast streams by local names