FISHES OF CHESAPEAKE BAY 
97 
The young when hatched are scarcely 10 millimeters (% inch) in length, but they grow rap- 
idly, reaching an average length of about 47 millimeters {V/s, inches) during the first half of July 
(computation based on 74 specimens taken from the Potomac River at Bryans Point, Md., on 
July 2 and 9, 1912); 66.5 millimeters ( 2 % inches) by the last half of August (computation based on 
5 specimens taken at Havre de Grace, Md., August 19, 1921, and also 30 specimens taken at Bryans 
Point, Md., August 23 and 30, 1912); and 70 millimeters (2% inches) by the last half of October 
(computation based on 138 specimens taken in the Potomac River at Bryans Point, Md., on the 
following daces: October 20, 1909, October 21, 1910, October 21, 22, and 28, 1911, and October 19 
and 23, 1912). 
The migration of the young shad to salt water begins with the approach of cool weather, but 
it is not until near the end of November or the beginning of December that all the young shad 
have left the fresh waters. The foregoing statement is based on investigations made on the Potomac 
River by Lewis Radcliffe and the late William W. Welsh. It is evident from the collections at 
hand that some of the young shad may remain in the salt water of the bay until they are a year 
or more of age, as specimens were taken on the following dates: January 15, 17, and 19, 1916, 
February 18 and 21, 1916, and March 6 and 21, 1916. Eight shad, taken in January, 1916, had 
an average length of 108 millimeters (4J4 inches); 3 taken in February, 1914, average 114 milli- 
meters (4^ inches); 10 specimens taken in March, 1916, average 142 millimeters (5Y% inches); and 
2 specimens taken in May, 1922, average 152 millimeters (6 inches). Two specimens taken in 
November (one in 1912 and the other in 1921), having lengths of 149 millimeters (6Ls inches) and 
243 millimeters (9^ inches) , may be in their second year, as they are very much larger than other 
specimens taken during the same month, although we are unable to observe anything in the struc- 
ture of the scales that suggests a “winter ring.” 6 We are aware that there are published accounts 
of shad having attained, under especially favorable circumstances, a length of 6 or 7 inches, or in 
one instance of 9 inches (Smith, 1907, p. 127), at the age of 7 months. At Washington shad placed 
in ponds with an abundant supply of young carp for food attained a length of 6 inches by early 
November, but shad kept in an aquarium at the Bureau of Fisheries in Washington attained a 
length of less than 4 inches at the age of 1 year. Bean (1903, p. 208) states that “ Nets set offshore 
in Gravesend Bay in the fall frequently inclose large quantities of young shad, sometimes a ton 
and a half at one time, during the migration seaward * * *. The fish are usually about 6 to 8 
inches long.” Bean, no doubt, assumed that these fish were the young of the last spawning season. 
However, in view of the fact that Chesapeake fish are only about 3 inches long in late fall, it is our opin- 
ion that these 6 to 8 inch shad probably were in their second year. As there are no “connecting links ” 
between our two individuals (6Lg and 9L£ inches) already mentioned and 140 other individuals at 
hand, taken during November, the largest of which is only 117 millimeters (4J^ inches) long, the 
question naturally rises as to whether or not these specimens belong to an older class. The growth 
of the shad apparently is not noticeably retarded by the approach of cold weather, and it appears 
to continue throughout the winter. The limited number of specimens taken during the winter 
probably are too few to permit of definite conclusions, but if the rate of growth should be even 
slightly more rapid during the winter than during the summer, as indicated by the specimens at 
hand, an explanation for the apparent absence of definite “winter rings” on the scales of adult 
shad becomes evident. (The suggestions on p. 88, relative to the sudden upward bend in the 
growth curve of P. sestivalis, may apply to the shad also.) No specimens of young shad, except 
fry, were taken during the present investigations from April to October, both inclusive. The exten- 
sive collecting that was done shows quite conclusively that a few of the young shad spend the 
first winter of their lives in the salt water of the bay, and furthermore, that if any at all remain 
until they are more than a year old it is only a rare straggler. 
8 For recent works on the age determination of the shad see “Age of shad ( Alosa sapidissivia Wilson) as determined by the 
scales,” by N. Borodin. Transactions, American Fisheries Society, fifty-fourth annual meeting, Quebec, Canada, Sept., 1924 
(1924) , pp. 178-184, 6 figs. Hartford. Also, “ A confirmation of Borodin’s scale method of age determination of Connecticut River 
shad,” by R. L. Barney. Ibid., pp. 168 to 177, 4 figs. 
