296 Memoir Sears Foundation for Marine Research 



Eye: diameter 3.8-5.7. 

 Inter orbital: width 4-55— 5-95- 

 Maxillary: length 11— 14. 

 Pelvic fin: length 9.9— 11. 9. 

 Pectoral fin: length 1 5.3-1 7.7. 



Scales: 52—62. 



Ventral scutes: 35-38. 



Gill rakers: 59-73 in adults. 



Fin rays: dorsal 17-20; anal 20-23; P^'^" 



toral 15-17. 

 Vertebrae: 55-57 (4 specimens), 54-59 



given in literature. 



Body slender, compressed, its greatest thickness generally about half of its depth; 

 the depth very variable, increasing with age, 2.75—4.0 in SL. 



Scales moderately adherent, with crenulate membranous borders, 15 or 16 rows 

 between base of pelvic fin and anterior dorsal rays. Ventral scutes well developed, 

 20-22 in front of pelvics, 14—17 behind them. 



Head 3.6-4.4 in SL. Snout 3.6-4.6 in head. Eye 4.0-5.9. Interorbital 4,2— 

 5.8. Mouth moderate, oblique; mandible included. Maxillary broad, its width about 

 half of length of snout, with a broad supplemental bone, rounded posteriorly; reaching 

 to middle of eye in young, generally to below posterior margin of eye in adults, 1.9—2.2 

 in head. Gill rakers increasing in number and proportionate length with age, those at 

 angle shorter than snout in young but longer than snout in large specimens, 26-43 

 on lower limb in young 29—125 mm SL, 59—73 in specimens 300 mm SL and upward. 

 Teeth missing in adults though present on jaws and median line of tongue in young. 



Dorsal fin somewhat elevated anteriorly, its margin slightly concave, Its last ray 

 a little longer than the preceding one, its origin an eye's diameter or less in advance 

 of pelvic fin and about equidistant between tip of snout and vertical from base of last 

 anal ray. Caudal rather deeply forked, the lobes of nearly equal length and somewhat 

 shorter than head. Anal low, Its origin about an eye's diameter nearer to base of 

 pelvic than to base of caudal. Pelvic near ventral edge, about equidistant between 

 base of pectoral and origin of anal, 2.1—2.6 in head; the axillary scale equal to, or a 

 little more than, half of length of fin. Pectoral a little higher on side than pelvic, 

 1.4— 1.65 in head. 



Color. Fresh specimens greenish to bluish with metallic luster above, gradually 

 shading into the bright silver on sides. Dark spot on shoulder, sometimes followed 

 by smaller spots or dots, rarely with a second parallel row of dots below the first. No 

 dark lines along rows of scales. Fins pale to greenish, the dorsal and caudal somewhat 

 dusky in large examples, and tips of lobes of caudal dark in some specimens. Peritoneum 

 mostly pale to silvery. 



Size. This species is the largest of the herrings. Females attain a maximum 

 length of about 600 mm (30 in.) and a weight of 12 pounds In the Atlantic. On the 

 Pacific coast, where the species was introduced, the maximum weight is even greater; 

 females of 14 pounds have been reported. In the Chesapeake Bay area the average 

 weight (and length) of females (roe shad) is probably somewhat under six pounds 

 (about 57,5 cm; 22.75 i"-)? '^'^^'^ °^ males (buck shad) about 3.5 pounds (about 50 cm; 

 20 In.). 



