108 



FISHERY BULLETIN OF THE FISH AND WILDLIFE SERVICE 



Shad Alosa sapidissima (Wilson) 1811 [Approxi- 

 mate date] 



Jordan and Evermann, 1896-1900, p. 427. 



Description. — The shad is a typical member of 

 the herring tribe in all respects with soft-rayed 

 dorsal and anal fins of moderate size, the former 

 situated above the ventrals and well forward of 

 the middle of the body. It has a deeply forked 

 tail and large scales that are loosened easily. 

 Unlike the sea herring, the shad has no teeth on 

 the roof of the mouth; adults have no teeth at 

 aU, although young shad have small ones in the 

 jaws which may persist until the fish is a foot or 

 so long. The shad agrees with the hickory shad, 

 alewife, and blueback, in its deep body and sharp 

 saw-edged belly. But it differs rather noticeably 

 from the hickory shad in its longer mouth, with 

 upper jaw reaching to below the rear edge of 

 the eye, and in the fact that the tip of its lower 

 jaw is entirely enclosed within the tip of the upper 

 when its mouth is closed. The most clear cut 

 character distinguishing shad from alewife and 

 blueback is that the upper outline of the shad's 

 lower jaw is very slightly concave, without a 

 sharp angle, the outline of theirs deeply concave 

 with a pronounced angle. Furthermore the lining 

 of the shad's belly is very pale. 



Color. — Dark bluish or greenish above, white 

 and silvery low on sides and on belly, with a 

 dusky spot close behind the rear edge of the gill 

 cover, and usually with one or two longitudinal 

 rows of indistinct dusky spots behind it. 



Size.— The shad is the largest of the herrings 

 that regularly visit our Gulf, growing to a length 

 of 2% feet. In the Bay of Fundy, according to 



Leim 96 shad weigh about % pound at 8 inches; 

 about % pound at 12 inches; about 1% pounds at 

 15 to 16 inches; about 2% pounds at about 20 

 inches ; and about 4 K pounds at 23 to 24 inches, 

 though with variations according to their condi- 

 tion. Adult males weigh from 1% to 6 pounds; 

 females from 2>}{ to 8 pounds. Shad are occasion- 

 ally reported to 12 pounds, and the older writers 

 mention shad of 14 poimds, but none so large has 

 been credibly reported in the Gulf of late years. 



Habits. — The shad, like the alewife, spends 

 most of its life at sea, and makes most of its 

 growth there, but runs up into fresh rivers to 

 spawn, the spent fish soon returning to salt water, 

 and its fry soon running down also. During then- 

 stay in the sea shad are schooling fish, often in 

 thousands, and they never reenter fresh water 

 until they return to spawn, though they sometimes 

 do appear in brackish estuaries. Schools of shad 

 are often seen at the surface in spring, summer, 

 and autumn. In winter they disappear from 

 sight. Probably the shad of the year winter near 

 the mouths of their parent streams; the larger 

 sizes somewhat farther out and deeper. The most 

 direct evidence as to the depths to which they 

 may descend is that shad have been trawled at 

 about 50 fathoms off Nova Scotia in March (see 

 footnote 22, p. 112), and at 26 to 68 fathoms off 

 southern New England in May (footnote 23, p. 

 112). 



Food. — The shad, like other herrings, is pri- 

 marily a plankton feeder. We have found shad 

 taken in the Gulf of Maine in summer full of 

 copepods (chiefly Calanus), and the stomach con- 



» Contrib. Canad. Biol.. N. Ser., vol. 2, 1924, p. 245, fig. 41. 



Figure 48.— Shad (Alosa sapidissima), Chesapeake Bay specimen. From Goode. Drawing by H. L. Todd. 



