NATURAL HISTORY OF THE QUINNAT SALMON. 
109 
when about 3 inches long, and grow to be 36 inches in twenty-four months, which 
would be an increase of about 1.4 inches per month. 
Gastric parasites . — Of 209 fresh- water specimens examined in the investigation 
of food of young salmon, 31 had parasites in the stomach. The parasites were of two 
or three kinds, one elongated, the others short and grain-like. They have not been 
studied, except to note the date and size of the fish. It is evident that residence in 
fresh water is conducive to the growth of parasites in the stomachs of young salmon. 
Month. 
Number 
examined. 
Number 
with 
parasites. 
Percent- 
age with 
parasites. 
Size. 
N umber 
examined 
N umber 
with 
parasites. 
Percent- 
age with 
parasites. 
January 
9 
i 
11 
1.1 to 2 inches _ - . 
01 
3 
5 
February 
ki 
0 
0 
2.1 to 3 inches . . . 
57 
3 
5 
March 
10 
o 
0 
3.1 to 4 inches . . . 
53 
10 
19 
April 
15 
0 
0 
4. 1 to 5 inches _ . . 
30 
12 
40 
May 
50 
1 
8 
5.1 to 0.3 inches.. 
8 
3 
38 
August 
20 
3 
15 
Total 
209 
31 
15 
September 
18 
3 
17 
< Ictober 
80 
8 
23 
November 
15 
3 
20 
December 
11 
8 
73 
Total 
209 
31 
15 
Diseased parrs . — Only two diseased young salmon from the streams have been 
met with. One was found dead, covered with fungus, near Sims in 1898; the other, 
5 inches long, was taken in the trap at Battle Creek, September 28, 1900. The upper 
lobe of the caudal fin was wanting, and the remainder, with the caudal peduncle, was 
covered with fungus. 
Mature male parrs . — In October, 1897, several mature males, between 4 and 5 
inches long, were taken at Sisson. In January, 1898, two males, 5.5 inches long and 
known to be only a year old, were taken above the Bear Valley dam near Olema; one 
was mature. In August, 1898, a 4-inch mature male was taken at Sisson. Four of 
the 6 young salmon taken at Fall River Mills in August, 1898, were males, all with 
the genital organs mature. Mature male parrs were frequently taken at Battle Creek 
fishery in October and November, 1898. The sex of a number of parrs, 4 to 6 inches 
long, from the general collection was determined; 15 were mature males, 2 immature 
males, and 12 were females. These mature male parrs can usually be distinguished by 
their more dusky color and by the slightly distended abdomen. Examined under the 
microscope, the milt is apparently the same as that from adults. A few eggs from a 
female of ordinary size were fertilized by milt from a 4.7-inch male. The fertilization 
was complete, all of the eggs hatched, and the alevins were of normal appearance. 
No explanation of this early maturing of males can be made, and nothing is 
known of their future history. They feed the same as other young salmon and appar- 
ently are not attracted by mature females as the adult males are. It may be that 
they return from the ocean as the stunted form known as grilse. It is probable 
that several months’ residence in fresh water causes the generative organs to mature 
both in the adults and in the young males. 
Temperature notes . — The following table shows the number of young salmon 
taken at one haul of the seine in water of various temperatures. It indicates but 
little, except that young salmon may reside during the summer in water having a 
temperature of 64 degrees. The 25 taken in Thomas Creek, with a temperature of 
68 degrees, were landlocked in a shallow pool. 
