664. U. S. BUREAU OF FISHERIES 
They spawn chiefly in November in shallow water (3 to 8 fathoms), preferably 
on a sandy or gravelly bottom. Very little is known about the young herring 
and many special efforts to obtain them have met with failure. As the 
herring generally have not been kept separate in the statistical reports, no 
definite information concerning their relative abundance is available at present. 
The eggs of the herring deposited in the fall sometimes hatch in the early 
spring, probably April. During the first year the young herring grow very 
rapidly. On the average, they reach a length of 5 inches in the first year, 
7.3 inches in the second year, 8.6 inches in the third year, 9.3 inches in the 
fourth year, 9.6 inches in the fifth, 10.2 inches in the sixth, and 10.8 inches 
in the seventh year; or, in terms of increments, they grow, during each year 
of life, beginning with the first year, 5, 2.3, 1.3, 0.7, 0.3, and 0.6 inches, respec- 
tively. If the length at the end of the seventh year is taken as 100 per cent, 
then the percentage of total growth completed at the end of the first year 
is 46.4, the end of the second year 67.5, at the end of the third year 79.6, 
at the end of the fourth year 85.8, at the end of the fifth year 89.1, and at 
the end of the sixth year 94.2. The herring complete nearly 50 per cent 
of their growth in length during the first year of life. Males and females 
grow at identical rates. 
The growth history, in terms of weight, is as follows: At the end of the second 
year the herring weigh about 3.53 ounces; at the end of third, 5.03 ounces; 
at the end of fourth, 5.61 ounces; at the end of fifth, 6.18 ounces; and at the end 
of the sixth year, 7.78 ounces. In the third year the herring gain 1.5 ounces in 
weight ; in the fourth, 0.58 ounce; in the fifth, 0.57 ounce; and in the sixth year, 
1.6 ounces. If the total weight at the end of the sixth year is taken as 100 per 
cent, then the percentage of total weight attained at the end of each preceding 
year is as follows: Year second, 45.4; year third, 64.7; year fourth, 72.1; and 
year fifth, 79.4. The females weigh slightly more than the males at corre- 
sponding ages, but this presumably is due to the slightly greater weight of the 
partly developed female sex organs. In comparison with length, the rate of the 
proportional total-weight increase is small during the first years of life, for 
while more than three-fourths of the total length reached by the species is 
attained at the end of the third year, more than five years are required for a 
similar increase in weight. In this connection, it may be of interest to know 
that Gilbert’s law of compensation in growth also applied to the lake herring. 
That is, it is found that, on the average, the big yearlings of a year class were 
the big fish of that year class in all sueceeding years of life, but that the 
differences between the small and large yearlings diminished in each year of 
age—that is, the small yearlings were rapid growers, the large yearlings slow 
growers. ; 
We do not know where the herring stay during the first two or three years of 
life. They do not appear in the commercial catches until their third year, 
when many attain sexual maturity. Very few second-year fish are taken in the 
commercial catches (0.2 to 0.8 per cent). Likewise few eighth-year fish are 
taken (0 to 0.4 per cent). ‘The percentage of seventh-year fish present varied 
from 9 to 1.8 per cent; that of the sixth-year herring from 1.8 to 9.9 per cent. 
The commercial catches are almost entirely composed of third, fourth, and fifth 
year fish, these age groups comprising 87.2 to 97.4 per cent of the entire catch. 
In 1921 the fourth and fifth year fish formed the bulk of the sample—72.9 per 
cent of the total. In the three succeeding years (1922, 1923, and 1924) the third 
and fourth year fish predominated, representing 78.4 to 84.8 per cent of the 
sample. In each year the fourth age group was the largest, its individuals com- 
prising 42.8 to 58.3 per cent of the total catch. I found that a shift occurred 
in the age composition; the percentage of third-year fish increased each year 
during the period 1921-1923 (14.3 to 32.8 per cent), and then remained sta- 
tionary in 1924 (82.7 per cent). This general increase occurred at the expense 
of the third-year fish mainly, which each year became progressively less abun- 
dant (30.1 to 19 to 17.3 to 11.8 per cent). 
In many species the commercial catches are dominated by one particular 
year class for two or more consecutive years. This does not occur in the lake 
herring. Each year class drops off rapidly in the years following the year of 
its dominance, which, as shown above, was the fourth. Every year a new year 
class predominates in the commercial catches. 
In general, the males and females are equally abundant. Of 2,950 herring, 
49.5 per cent were males and 50.5 per cent females. The relative abundance of 
each sex does vary, however, during the course of the spawning run; the males 
are more numerous than the females early in the season but less numerous 
late in the season. 
