FISHES OF CHESAPEAKE BAY 
87 
April 1 and 20 in the lower bay. The numbers decrease throughout May, until after June 1 only 
stragglers are caught. At Havre de Grace notes made by the late William W. Welsh in 1912 
record the first catch of glut herring on April 11 and the height of the run on about April 27. Of 
course, it is well known that the time of arrival and the height of the run vary somewhat from year 
to year, but in general the glut herring is expected in the lower Chesapeake region the first half 
of April and in the upper reaches of the bay during the last half of April. This species does not 
ascend fresh-water streams as far as the branch herring, and spawning takes place at a shorter 
distance from the sea. The greater part of the young, as in the branch herring, appear to pass 
through Chesapeake Bay and out to sea upon the approach of cold weather, but a few stop in the 
deeper waters of the bay during their first winter and very few apparently remain there for the 
second winter. 
The rate of growth 5 in the young of this species appears to be somewhat more rapid than in 
the branch herring. The size attained at a given age is quite uniform, as no difficulty was expe- 
Fig. 49 . — Pomolobus .aestivalis. Note deep mandible and Fig. 50.— Pomolobus aestivalis. Note that mandible scarcely 
sharp angle on its upper margin projects and that it does not enter dorsal profile 
rienced in separating young fish into year groups. Specimens taken in March, for example, clearly 
fall into two separate lots, one group consisting of individuals that are in their first year and the 
other group comprising those in their second year. The uniformity in size of the young of a certain 
age suggests a short spawning period. The young of the branch herring, on the other hand, vary 
greatly in size, and much difficulty was experienced in separating into year groups catches taken 
* The eggs, embryology, and larval development of the glut herring are described by Kuntz and Raddiffe (1918, pp. 123 to 126, 
figs. 87 to 100). 
