28 BULLETIN OF THE BUKEAU OF FISHERIES 



or after October. The specimens captured there usually have been about 5 feet 

 long, and very rarely does a full-grown tiger shark stray so far from its tropical 

 home. But, curiously enough, one at least of the several specimens recorded from 

 Provincetown, its furthest known outpost and the only locality where it has been 

 captured in the Gulf of Maine, must have been of good size, for its stomach contained 

 a whole full-grown swordfish. 



Habits. — This slender, active, and voracious shark, with wide jaws and powerful 

 teeth, is an inhabitant of the high seas, preying upon the large sea turtles, other 

 sharks, fish, and occasionally on invertebrates such as horseshoe crabs, crabs, 

 conchs, whelks, etc. Remnants of squeteague, mackerel, hake, scup, menhaden, 

 goosefish, and dogfish all have been found in stomachs of tiger sharks taken at Woods 

 Hole. 20 In the West Indies it is much dreaded, whether or not with good cause. 

 So seldom does this species round Cape Cod (in fact none has been reported east or 

 north of the cape for many years) that the chance of running across one in the Gulf 

 of Maine is extremely remote. It has never been recorded from the offshore banks. 



6. Great blue shark (Galeus glaucus Linnaeus) 



Blue Shark 



Jordan and Evermann (Prionace glauca Linnaeus), 1896-1900, p. 33. 

 Garman, 1913, p. 145. 



Description. — The blue shark is slender bodied, thickest at about its mid- 

 length, and tapering thence toward the head and tail (that is, the shape usually 

 named "fusiform"), its long pointed snout separating it at a glance from the blunt- 

 nosed tiger. The first dorsal is of moderate size, standing well behind the middle 

 of the space between pectorals and ventrals. The pectorals are very long, their 

 tips reaching as far back as the first dorsal, and their very narrow and pointed 

 outlines, combined with the location of the first dorsal and the pointed snout, give 

 it an aspect very different from that of the dusky shark, which resembles it in the 

 relative sizes of the fins. The second dorsal is less than half as high as the first — 

 about equal to the anal over which it stands. The lower lobe of the tail is only 

 one-third as long as the upper. The latter is notched near the tip, and both tail 

 lobes are sharp pointed. 



The teeth of the blue shark are very characteristic, being large and serrate, 

 each series forming a continuous cutting edge. Those of the upper jaM T are broadly 

 triangular with curved tips, while the lower teeth are narrower, pointed, and stand 

 more erect. 



Size. — The blue shark grows to a length of about 12 feet. 



Color. — The color varies from grayish to light or bright steel blue, or even to 

 bluish black above. Below it is dirty white. 



General range. — Cosmopolitan in the warmer parts of all oceans. On the 

 northeastern coast of North America it is taken from time to time at Woods Hole, 



!0 Bell and Nichols (Copeia, No. 92, Mar. 15. 1921, pp. 17-20) list the stomach contents of a large number of tiger sharks caught 

 off Morehead City, N. C. 



