96 Commercial Shark Fishing in the Caribbean Area 



Figure 32 



Family Rhincodontidae, Whale Sharks. Only five gill openings; 

 two dorsal fins and an anal fin ; the second dorsal and the anal 

 much smaller than the first dorsal; the caudal is about 1/4 of the 

 total length of the shark and is crescent shaped, with its axis 

 raised steeply above the general axis of the body. The mouth is at 

 the tip of the snout; the nostril does not have a barbel; the inner 

 edges of the gill arches are connected by a sponge-like mass of 

 tissues which acts as a sieve, through which water is forced when 

 the mouth is closed. In this way, minute organisms and small 

 fishes are gathered to be swallowed. The structure is unique 

 .among sharks. 



Genus Rhincodon, Whale Sharks. Characters as above. 



Figure 32. Rhincodon typus, Whale Shark. 



Description: Trunk rather stout Avith two prominent ridges 

 along each side ; head broadly rounded in front without any dis- 

 tinct snout ; the mouth at the front tip of the head (this character 

 is unique among West Indian sharks) ; nostril very close to mouth 

 but not connected with it ; eye very small ; gill openings large but 

 high up on the sides of the neck; the fifth gill opening over the 

 origin of the pectoral fin ; teeth similar in the two jaws, conical, 

 very small, in 10 to 15 functional series and very numerous — an 

 18-foot specimen having a total of about 3,600 in each jaw and 

 larger specimens still more. First dorsal fin overlaps pelvics ; sec- 

 ond dorsal only about 1/3 as large in area as first; lower rear edge 

 of upper lobe of caudal is not notched near the tip (it is so notched 

 in most other local sharks) ; lower lobe about 3/4 as long as upper; 

 pelvics only about as large as second dorsal ; and pectoral with 

 noticeably concave distal margin. 



Color: Upper parts dark grayish, reddish or greenish brown, 

 conspicuously marked with round white or yellow spots and with 

 a variable number of white or yellow cross stripes. Lower parts 

 are plain whitish or yellow. 



Size: The smallest specimen yet measured was 6 feet long, the 

 largest about 45 feet. It is credibly reported to grow to a length of 

 60 feet or even more. The estimated weight of one of 38 feet was 

 26,594 pounds. The size at which sexual mating is reached is not 

 known, nor is it yet known whether or not the eggs hatch within 

 the mother before birth. 



Habits: About all that is known of its habits is that it gathers 

 in schools, that it often basks at the surface and that it is so little 

 alert that one is rammed by a steamer from time to time. It feeds 

 on small Crustacea, but perhaps more often on schools of small 

 fish such as anchovies. It obtains these by swimming open- 

 mouthed and then driving water out through its branchial sieve 

 thus separating the prey. Whale sharks have often been seen so 

 employed at the surface, sometimes while vertical in the water. 



Range: Tropical belts of all the great oceans. Reported from 



