38 



FISHERY BULLETIN OF THE FISH AND WILDLIFE SERVICE 



feet; and 1,028 to 1,395 pounds at 13 to 14 feet. 88 

 Habits. — This voracious shark, with wide jaws 

 and powerful teeth, preys upon the large sea 

 turtles, other sharks, fish, and occasionally on 

 invertebrates such as horseshoe crabs, crabs, 

 conchs, whelks. It is proverbial for its habit 

 of feeding on slaughter-house wastes or any other 

 carrion. Remnants of squeteague, mackerel, 

 hake, scup, menhaden, goosefish, and dogfish all 

 have been found in stomachs of tiger sharks taken 

 at Woods Hole. 87 There is no placental connec- 

 tion between mother and young, and the broods 

 are very large, as many as 82 having been counted 

 in a large female; but other litters as small as 

 10 to 14. In the West Indies it is much dreaded, 

 whether or not with good cause. 



General range. — Cosmopolitan in the warmer 

 waters of all oceans; straying northward as far 

 as Cape Cod on the American coast of the Atlantic. 

 Occurrence in the Gulf of Maine. — A few tiger 

 sharks are taken in fish traps in the Woods Hole 

 region every year, seldom before August or later 

 than October although one was caught there July 20, 

 1951. 88 These specimens usually have been about 

 5 feet long, at most about 8 feet, and very rarely 

 does a full-grown tiger shark stray so far from 

 its tropical home. The tiger has not yet been 

 recorded (on reliable evidence) from within the 

 limits of the Gulf of Maine. It is included here 



M For further details and references, see Bigelow and Schroeder, Fishes 

 Western North Atlantic, Pt. 1, 1948, p. 269. 



»' Bell and Nichols (Copela, No. 92, March 1921, pp. 17-20) list the stomach 

 contents of a number of tiger sharks caught off Morehead City, N. C. 



" This shark was 8 feet, 3 Inches long, taken In a pound net off Quisset 

 Harbor, Buzzards Bay. 



because of the likelihood that a stray specimen 

 may occasionally round the elbow of Cape Cod, 

 or be encountered on the offshore Banks. 89 



Blue shark Prionace glauca (Linnaeus) 1758 



Blue dog 



Bigelow and Schroeder, 1948, p. 282. 



Garman, 1913, pi. 3, figs. 1-3 (as Galeus glaucus). 



Description. — The blue shark is slender-bodied, 

 thickest about its mid-length, and tapers toward 

 head and tail (a shape usually named "fusiform"). 

 Its snout is long with rounded tip. Its first dorsal 

 fin is of moderate size, standing far back with the 

 mid point of its base about midway between the 

 inner corners of the pectorals (when these are laid 

 back) and the points of origin of the pelvic fins. 

 The second dorsal fin is less than one-half as high 

 as the first, and is about equal in size to the anal 

 over which it stands. The pectorals are narrow 

 and very long, their tips reaching back nearly as 

 far as the rear corner of the first dorsal. The 

 lower lobe of the caudal fin (measured along its 

 anterior edge) is about one-half as long as the 

 upper lobe; the latter is conspicuously notched 

 near the tip, and both of the lobes of the caudal 

 fin are slender tipped. 



The teeth are large, sharp-pointed, with serrate 

 edges, and distinctive in shape. The uppers are 

 so closely spaced that the bases of adjacent teeth 



" The statement In the first edition that a tiger shark was once taken at 

 Provlncetown was an error. The original description of the specimen In 

 question (Atwood, Proc. Boston Soc. Nat. Hist., vol. 10, 1865, p. 81) suggests 

 that it was a mako (Isurus oxyrinchus) . 



Figure 12. — Blue shark (Prionace glauca), male, about 7 feet 2 inches long, off Marthas Vineyard. A, third left-hand 

 upper tooth, counted from mid-point of jaw; B, ninth left-hand upper tooth; C, third left-hand lower tooth; and 

 D, eighth left-hand lower tooth; about 1.6 times natural size. From Bigelow and Schroeder. Drawings by E. N. 

 Fischer. 



