88 
BULLETIN OF THE BUREAU OF FISHERIES 
in the bay on various dates. This large variation in size of young taken on the same date suggests 
a rather protracted spawning period. 
A large number of young glut herring taken in fresh water, principally in 1912, had attained 
an average length of 28 millimeters (1% inches) on July 1 , 46 millimeters (Iris inches) on September 
1, and 64 millimeters (2^ inches) on December 1. A decided upward jump takes place in the growth 
curve between the last lots taken in fresh water and those taken in the salt water of the bay. The 
reasons for this sudden upward curve are not definitely known and the subject needs further inves- 
tigation. The two possible reasons that have occurred to us are (1) that growth is greatly exhil- 
arated when the fish enters salt water; this explanation is rendered somewhat unlikely because of 
the cold winter weather; (2) it seems probable that the smaller individuals of the season’s brood 
remain in fresh water later than the larger ones, and therefore the lots taken late in the fall in fresh 
water consist of fish that are either “runts” or hatched late in the season, whereas the catches in 
January and February from the bay consist of fish of more average growth. It seems altogether 
unlikely that the fish from the bay belong to a different year class. A limited number of specimens 
taken in the deeper waters of the bay had reached an average length of 82 millimeters (3M inches) 
by February 1 and 90 millimeters (3)^ inches) by April 1. A few individuals taken in Chesapeake 
Bay, which probably were in their second year, had attained an average length of 174 millimeters 
(6% inches) on February 1. 
The maximum length attained by the glut herring is about 380 millimeters (15 inches) and the 
weight 13 ounces. The average length of market fish, however, is only about 280 millimeters 
(11 inches) and the weight 7 ounces. 
Length frequencies of 2,035 glut herring, Pomolobus sestivalis 
[Measurements in millimeters, grouped in 5-millimeter intervals] 
Total 
length, 
June 
July 
Aug. 
Sept. 
Oct. 
Nov. 
Dec. 
Jan. 
Feb. 
Mar. 
Apr. 
May 
milli- 
meters) 
1-15 
16-30 
1-15 
16-31 
1-15 
16-31 
1-15 16-30 
1-15 
16-31 
1-15 
16-30 
1-15 
16-31 
1-15 
16-31 
1-15 
16-28 
1-15 
16-31 
1-15 
16-30 
1-15 
16-31 
20-24 
22 
25-29 
4 
30-34 
2 
35-39 
1 
3 
2 
40-44 
13 
34 
10 
2 
1 
1 
45-49 
10 
38 
33 
25 
19 
4 
50-54 
2 
12 
5 
19 
36 
47 
7 
3 
55-59 
1 
5 
2 
4 
11 
71 
21 
9 
60-64 
2 
2 
33 
44 
29 
65-69 
i 
i 
4 
29 
31 
1 
2 
1 
2 
70-74 
2 
5 
3 
3 
4 
1 
2 
4 
75-79 
25 
16 
9 
17 
39 
80-84 
76 
21 
56 
67 
128 
85-89 
81 
5 
68 
123 
139 
90-94 
52 
7 
40 
87 
56 
95-99 
18 
1 
30 
25 
45 
2 
100-104 
16 
1 
15 
11 
14 
2 
105-109.-- 
2 
4 
5 
7 
1 
110-114 
1 
i 
1 
115-119... 
1 
1 
2 
120-124... 
125-129... 
2 
130-134... 
135-139... 
140-144... 
i 
145-149 
150-154. __ 
1 
155-159. .. 
1 
1 
160-164... 
2 
1 
2 
2 
165-169... 
3 
1 
170-174... 
3 
1 
175-179... 
4 
180-184... 
1 
185-189... 
1 
190-194... 
1 
1 
195-199... 
1 
1 
205-209... 
1 
Total. . 
27 
31 
93 
51 
50 
70 
162 
106 
75 
286 
57 
238 
346 
435 
8 
n° 
