282 Memoir Sears Foundation for Marine Research 



Prionace glauca (Linnaeus), 1758 



Great Blue Shark 



Figures 47, 48 



Study Material. Twenty freshly caught specimens (2 females and 18 males), about 

 5 to 1 1 feet long, from various localities in the Gulf of Maine, Georges Bank and from 

 the offing of southern New England (jaws preserved) ; four preserved specimens, 539 to 

 2,160 mm. long, from Georges Bank and southern New England; Japanese specimen 

 1,675 mm. (about 5 feet 6 inches) ; also several other large specimens caught ofiF the New 

 England coast but not measured, and many seen at liberty. 



Figure 47. Prionace glauca, male, about 2,175 ™™- l°ng) from Martha's Vineyard, Massachusetts (Harv. Mus. 

 Comp. Zool., No. 36035). A Head from below, about % natural size. B Left nostril, about natural size. C Der- 

 mal denticles, about 25 x. Z) Lateral and apical views of dermal denticle, about 25 x. £ Left-hand upper and 

 lower teeth, about % natural size. F Third upper tooth. G Ninth upper tooth. H Third lower tooth. / Eighth 

 lower tooth. F-I, about 1.5 x. 



Distinctive Characters. The Blue Shark is easily distinguished from other West 

 Atlantic Sharks of its family by the combination of very long pointed snout, long falcate 

 pectorals, first dorsal fin set far back, teeth, and brilliant blue upper parts. 



Description. Proportional dimensions in per cent of total length. Male, 2,175 mm., 

 from Martha's Vineyard, Mass. (Harv. Mus. Comp. Zool., No. 36035). Male, 2,442 

 mm., from oflF Nauset, Cape Cod, Mass. (field specimen). 



