18 DANGEROUS MARINE ANIMALS 



The tiger shark tends to be somewhat of a scavenger in its eating 

 habits. The distinctive characters of this species are the teeth, a 

 very short snout, and a sharply pointed tail. The color is gray or 

 grayish brown, darker above than on sides and belly. The oblique 

 or transverse bars on the sides and fins are usually present only in 

 the smaller specimens. Said to attain a length of 30 ft., but the 

 largest recorded specimen was 18 ft. The tiger shark is widespread 

 in the tropical and subtropical belts of all oceans, inshore and off- 

 shore alike. Said to be the commonest large shark in the tropics. 

 Lemon Shark, Negaprion brevirostris (Poey). (Fig. 2, Bottom). 

 Little is known of its habits. The lemon shark is commonly found in 

 saltwater creeks, bays and sounds, and around docks. It is believed 

 to be the cause of a number of attacks on humans in South Carolina 

 waters. Distinctive characters are the second dorsal fin that is 

 nearly as large as the first, broadly rounded snout, and its teeth. 

 Attains a length of about 11 ft. Color yellowish brown above or 

 dark bluish gray, sides and belly yellow or olivaceous. Inshore, 

 western Atlantic, northern Brazil to North Carolina, tropical West 

 Africa. 



Lake Nicaragua Shark, Car char inus nicaraguensis (Gill and 

 Bransford). (Fig. 3, Next to Top). Little is known of the habits of 

 this shark, except that is comes commonly into very shallow water, 

 although it is seldom seen at the surface. A number of well-authen- 

 ticated human attacks are credited to this shark. Color is dark gray 

 above, very light below. Said to attain a length of 10 ft., but usually 

 smaller. This is a freshwater species and is confined to the fresh- 

 waters of Lake Nicaragua, its tributaries and outlet. 



Dusky Shark, Carcharhinus obscurus (Lesueur). (Fig. 3, Next to 

 Bottom). Little is known of the habits of this shark. Frequently 

 found in shallow water. Back and upper sides, bluish or leaden 

 gray, sometimes pale, lower parts white. Lower surfaces of pec- 

 torals grayish and sooty toward tips. Attains a length up to 14 ft. 

 Tropical and warm-temperate waters on both sides of the Atlantic. 



White-tipped Shark, Ptcrolamiops longimanus (Poey). (Fig. 3, 

 Bottom). This shark has been accused of being a man-eater by 

 reliable authorities. It is definitely known to be almost indifferent 

 and fearless in its contacts with man. The white-tipped shark is a 

 relatively slow-swimming and sluggish species. The distinctive 

 characteristics of this shark are the broadly rounded apex of the 

 first dorsal fin, the convexity of the posterior outline of the lower 

 caudal lobe, and a very short snout in front of the nostrils. The 

 shark is light gray or pale brown to slaty blue above and yellowish 



