THE LOWER FISHES 153 



REQUIEM SHARKS: Family Carcharinidae 



These sharks form the bulk of "typical" modern sharks and are characterized 

 by a large first dorsal fin which is usually far anterior to the pelvic. The second 

 dorsal is much reduced, just above and of a similar size to the anal. Added field 

 marks are the position of the fourth and fifth gill slits over the pectoral fins 

 and the characteristically shaped caudal fins, which is preceded by well-developed 

 precaudal pits. These fishes all have a well-developed third eyelid or nictitating 

 membrane which serves to keep the eyes free of foreign matter (fig. 64^ 

 Spiracles are small or missing. The teeth are bladelike, triangular, and trenchant, 

 and only one row is functional at a time. Requiem sharks are ovoviviparous or 

 viviparous and characteristic of warm temperate to tropical seas the world over. 



TIGER shark: Galeocerdo cuvier 



Size: Common at 12 feet. Said to reach 30 feet, but largest recorded in 

 Atlantic was 18 feet. 



Weight: Common at 850 pounds. 



Distribution: Common in the Caribbean. North to Cape Hatteras and rarely 

 to Cape Cod. On the West Coast to southern California. Cosmopolitan in warm 

 temperate and tropical seas. 



Identification: The snout is very blunt and rounded and the labial furrow 

 prominent. The sides are blotched and striped, but this pattern disappears with 

 age. The teeth are large, few in number, and characteristic (fig. 48^. 



Hahits: This is one of the most voracious sharks, having extremely catholic 

 tastes in food. It eats sea turtles, sea lions, fishes large and small, crustaceans, 

 offal, and other sharks. It also preys on sting rays, the spines having little effect 

 on the shark. One, when captured, vomited the arm of a man who had been 

 murdered at sea and dismembered. This is the most abundant large shark of 

 the Caribbean and seems to be attracted by the cast-off offal of slaughterhouses. 

 In such dumping areas, it may be dangerous. There are records of its having 

 attacked man, though these are few even in areas of shark abundance. In spite 

 of the foregoing, this is a sluggish shark, normally becoming active only when 

 aroused to the "feeding mood." One expects to see tiger sharks in shallow water 

 near land, but they may be encountered almost anywhere, even in harbors or 

 the deep sea. It is the most prolific shark, normally bearing thirty to fifty living 

 young. The largest number of young ever recorded in a brood, eighty-two, was 

 from a female of this species. The young are small, only 18 inches long at birth. 



e^ 



Fig. 61. Tiger shark. 



