3 04 Memoir Sears Foundation for Marine Research 



Relationships. There are two well-marked species of this genus in Europe, A. alosa 

 and A.finta, both of which have the deep cheek and notched upper jaw as in American 

 species. However, A. alosa has smaller scales (72-80 lateral series) and more numerous 

 gill rakers (72-86 on lower limb in adults) than the American species. A.finta, while 

 agreeing with the American species as to scales, has only about 24-32 gill rakers on 

 the lower limb, in grown examples. 



The two American species recognized here, namely A. sapidissima and A. ala- 

 bamae, differ principally in the number of gill rakers; mature examples of sapidissima 

 have 59-73 on the lower limb whereas specimens of alabamae of similar size have 

 only 41-48. The relationship of these species is discussed further in the account of 

 alabamae (pp. 309, 310). 



Variations. The specimens examined, from various localities within the range 

 (p. 295) and used in preparing the Description, do not differ specifically or subspecifically. 

 However, racial differences have been recognized. Vladykov and Wallace have found 

 slight average differences in the number of vertebrae, pectoral rays, and ventral scutes 

 between examples from the Bay of Fundy, Delaware Bay, and Chesapeake Bay; these 

 they regarded as different "populations" {130: 52—66). Investigators of the U.S. Fish 

 and Wildlife Service, in a special study of A. sapidissima, found that virtually every 

 important river system within the range of this fish is inhabited by a different race 

 (unpublished data). 



Commercial Importance. This species has been an important foodfish throughout 

 its entire range since the earliest settlers arrived, and no doubt these fish were taken 

 by the Indians long before. Unfortunately, pollution, overfishing, and dams constructed 

 across the streams (preventing the fish from reaching their spawning grounds) have 

 caused partial and sometimes serious depletion, or even virtual extermination. So 

 many streams have been dammed, particularly in New England, that, in the words 

 of Bigelow and Welsh: "the local stock of shad has diminished until now the Gulf of 

 Maine stock is but a shadow of its former abundance . . ." {16: 1 14). The great decline 

 in abundance in New England is evident from the published statistics of the former 

 United States Fish Commission, U. S. Bureau of Fisheries, and the present U. S. 

 Fish and Wildlife Service;" the annual New England catch between 18 89-1 908 

 seems to have been well above 1.25 million pounds, by 1919 it had fallen somewhat 

 below a million pounds, and between 1 924-1 940 it has fluctuated around a half 

 million pounds. 



The situation with respect to the American Shad fishery In the Hudson is much 

 more encouraging, although depletion occurred in that river also; statistics from the 

 sources previously mentioned show that the catch in that river declined from 3.75 

 million pounds in 1901 to only 40,000 pounds in 191 6 and to 43,000 in 1917; there- 

 after, between 191 8— 1935, *^he catch varied from 94,000 pounds (1924) to 847,000 



27. No adjustment for the differences in the number of persons employed, the type and number of vessels, and the 

 different types of gear used from year to year has been made in the statistics given here and elsewhere. However, 

 it is highly probable that the "fishing effort" for looo pounds of fish, for example, has increased. 



