98 Commercial Shark Fishing in the Caribbean Area 



Figure 33 



Family Orcctolobidac, Nurse Sharks. Only five gill openings, 

 the fourth and fifth (sometimes the third also) over the origin 

 of the pectoral; caudal peduncle not flattened above and below; 

 without longitudinal keels, either above or below; spiracle present; 

 nostril connected with the mouth by a groove, its front margin 

 with a prominent fleshy barbel. Two dorsal fins, the first over the 

 pelvics; second dorsal fin not much smaller than first; caudal 

 without a definite lower lobe, its axis raised but little above the 

 main axis of the trunk; teeth small and numerous. 



Genus Ginglymostoma, Nurse Sharks. No fleshy lobes on sides 

 of head ; the second dorsal originates anterior to the origin of the 

 anal ; the spiracle is very small. 



Figure 33. Ginglymostoma cirratum, Nurse Shark. 



Description: Trunk moderately stout; snout broadly rounded 

 and noticeably short. The nasal barbel (the most distinctive 

 feature) reaches back as far as the mouth; eyes very small; gill 

 openings noticeably short, the fourth and fifth very close together 

 over the origin of the pectoral ; mouth transverse and nearly 

 straight with very prominent labial furrows at the corners on both 

 jaws; teeth 15 to 18 on each side of upper jaw and 14 to 16 each 

 side below, similar in the two jaws, with high triangular central 

 cusp, flanked on either side by 1 to 3 smaller ones; the first dorsal 

 is over the pelvics, the second dorsal is nearly as large as the first 

 and similar to it in shape ; lower rear margin of the caudal is 

 nearly straight ; the anal a little smaller than the second dorsal ; 

 the pectoral broad and short with nearly straight distal edge and 

 with rounded corners. 



Color: Yellowish or grayish brown above; a paler shade of the 

 same hue below. Small ones are variously marked with small dark 

 spots and cross-bars, but adults often lose these markings. 



Size: No greater than one foot, it matures at 5 feet or even less, 

 often growing, however, to 11 to 12 feet. It occasionally grows as 

 large as 14 feet. An SMj-foot specimen will weigh 330 to 370 

 pounds. 



Habits: Found chiefly inshore and often in water only two or 

 three feet deep, as in channels among the Mangrove Keys and on 

 sand flats, bars, etc. It is sluggish and easily approached. It feeds 

 chiefly on invertebrates, such as shrimps, crabs, spiny lobsters ; also on 

 sea urchins or squids and on small fish. It bites greedily on almost any 

 bait. They come into very shallow water to mate, and pairs, so en- 

 gaged, are often seen. 



Range: Both sides of the tropical and subtropical Atlantic. 

 This is one of the more common sharks throughout the West 

 Indian-Caribbean region and has been reported from many locali- 

 ties from southern Brazil to southern Florida. In summer it 

 ranges northward both to the northern shores of the Gulf of 

 Mexico and to North Carolina, occasionally even farther along 

 the east coast of the United States. 



