4 8 Memoir Sears Foundation for Marine Research 



47): total number on first branchial arch in 70 young below eight inches, 15-24 (av. 

 20.4); in 800 large individuals 8—91 inches, 16—27 (av. 21.5). This difference was 

 due to the fact that in young specimens not all rakers were developed as yet on the 

 upper limb. Therefore, for purposes of comparison of gill raker counts, only individuals 

 above eight inches FL should be used. In 70 large specimens of ^. oxyrhynchus, 9—14 

 (av. 1 1.5) rakers on lower limb and 7—13 (av. 9.8) on upper limb. 



Caudal fin with average difference between TL and FL, i4''/o of FL; a notch 

 at tip of upper caudal lobe in undamaged specimens. 



Color. There is no significant difference in coloration between young specimens 

 and adults.^" Back and top of the head bluish-black, becoming progressively paler 

 down the sides; entire lower surface whitish. Median carina and spine on dorsal shields 

 (in dorsal row) whitish, contrasting strongly with darkly pigmented back, particularly 

 with the jet-black skin covering the extremities of each shield, the dorsal row thus 

 appearing as a series of whitish spots on a dark background. Upper half of lateral 

 shields of same color as background, but central and lower part of these shields whitish, 

 contrasting well with pigmented sides of fish, but not as sharply as in the case of the 

 dorsal shields. Sides of head and body, including ventral row of shields, white. Iris 

 pale golden. Anterior edge of pectorals, ventrals, and lower caudal lobe white, clearly 

 defined against remaining dark grey part of these fins; anal fin entirely white; dorsal 

 fin and upper caudal lobe dark grey or blue-black in the central portion, their broad 

 posterior margins whitish. Intestinal tract and peritoneum nearly white, never darkly 

 pigmented. 



The coloration of the three species that occur on the Atlantic coast of America, 

 when preserved in 4— 5*/o formalin, is characteristic. In A. oxyrhynchus, the ventral sur- 

 face and sides of the fish, even after a long period in perservative, are whitish or faintly 

 pinkish. The skin of the two other species {brevirostris and fulvescens), however, soon 

 acquires and permanently retains a green color that is particularly pronounced on the 

 unpigmented parts of the body, such as the ventral surface, sides of the head, etc. 



Size. Ryder found that females averaged about 8 feet TL, and sometimes 

 reached 10 feet, whereas males ranged between 6—7 feet (65: 268). Weights and total 

 lengths of two specimens taken in the Hudson River in 1936 and recorded by the 

 New York State Conservation Department were as follows: unspent male 7 feet 4 

 inches, 176 pounds; a spent male 8 feet 4 inches, 199 pounds 15 ounces. For the Gulf 

 of Maine, Bigelow and Schroeder (jj: 82) stated that "about 12 feet is perhaps the 

 greatest length to be expected today. But i 8 feet, reported for New England many 

 years ago, may not have been an exaggeration. . . . The heaviest Gulf of Maine Sturgeon 

 reliably reported (to our knowledge), was one of 600 pounds, landed in Portland by 

 the steam trawler Fabia from Georges Bank, December 21, 1932." A 14-foot female, 

 weighing 8 1 1 pounds, was caught at Middle Island Maguerville, about 64 miles off 

 the estuary of the St. John River, New Brunswick, in July 1924.'' 



36. For color illustrations of an adult Atlantic Sturgeon, see Vladykov {82: 7). 



37. Caught by Mr. John Neilson of Moncton. This information was kindly furnished by Mr. J. Raymond Tippett, 

 Moncton, New Brunswick, a Sturgeon fisherman himself. 



