348 Memoir Sears Foundation for Marine Research 



Body elongate, compressed, its greatest thickness varying greatly, from nearly 

 half of depth in large fat fish in spawning condition to only about a third of depth in 

 lean half-grown examples; greatest depth generally at, or slightly in advance of, vertical 

 from tip of pectoral, 2.5—3.3 in SL in specimens 100 mm and upward; ventral outline 

 moderately convex anteriorly, usually only half of greatest depth below a straight line 

 through lower margin of eye to middle of base of caudal. Caudal peduncle rather 

 slender, 2.9—4.0, usually 3.2—3.8, in head, and 3.2—4.1, but usually 3.5—4.0, in greatest 

 depth of body. 



Figure 86. Brevoortia tyrannus, 320 mm TL, 247 mm SL, Chesapeake Bay, USNM 129809. Drawn by 

 Ann S. Green. 



Scales adherent, the exposed part notably deeper than long, the scale itself some- 

 what deeper than long (Fig. 85 b); margin irregular in young about 60 mm long; 

 short blunt serrae on margin in examples of about 100 mm, the serrae increasing in 

 length with age, becoming slender hair-like appendages, often extending nearly across 

 the exposed portion of the next scale in large specimens; scales greatly reduced in size 

 on upper part of side, on back, and at base of caudal ; in rather regular series on lower 

 half or so of side; most frequently 3 or 4 vertical rows of scales exposed between tip 

 of pectoral and base of pelvic. A row of large modified scales on each side of median 

 line of back in front of dorsal fin, these scales not fully modified in specimens under 

 about 125 mm TL, rather variable in number, most frequently 34—38 in each series. 

 Ventral scutes rather strong, 17-22, usually 18-21, in front of pelvic fins; 10-15, 

 usually 12—14, behind these fins. 



Head 2.8-3.5, usually 2.9-3.2, in SL, its depth 3.1-4.0, usually 3.3-3.8. 

 Snout only moderately blunt, with a prominent median notch in adults, the length 

 3.9—5.5, usually 4.0-4.7, in head. Eye difficult to measure accurately in adults 

 because of much adipose tissue, about 4.4—6.2. Interorbital 4.2—5.3, usually 4.4— 

 5.0. Cheek deeper than long except in young. Maxillary rounded, generally scarcely 

 reaching below posterior rim of eye, the length 1.9—2.7, usually 2.1-2.5, in head. 

 Mandible included in upper jaw, its upper margin (within mouth) nearly straight. 



