150 



UNDERWATER GUIDE TO MARINE LIFE 



extremely powerful. One stroke of the tail can easily stave in a small boat. 

 These fish travel singly, in small groups, or in large schools of up to a hundred. 

 At times, several may travel in tandem and have been mistaken for sea serpents. 

 As is often the case with many giant fishes, these are plankton feeders, 

 having fine gill rakers with which to strain their food from the water. When 

 feeding, they travel open-mouthed through the water. Excellent pictures of this 

 may be seen in the motion picture Men of Arran. Basking sharks sometimes 

 leap from the water. They have been decimated by oil hunters; a single liver 

 yields from sixty to six hundred gallons of oil. They are usually seen only in 

 summer when the plankton supply is good, retreating to deeper water and 

 possibly not feeding in winter. 



WHALE SHARKS: Family Rhineodontidae 



There is no fish that approaches the whale shark in size except the basking 

 shark. The last two gill slits are over the pectoral fin, and the first dorsal is 

 fairly far back over the small pelvics. The tail fin is huge. The mouth is large 

 and not preceded by a snout. There is only one species of cosmopolitan tropical 

 distribution. 



Fig. 57. Whale shark. 



WHALE shark: Rhincodon typiis 



Size: To 60 feet or more. Very rare over 30 feet. 



Weight: A 38-foot whale shark weighed 26,594 pounds. 



Distribution: All tropical seas. Most numerous off the Philippines and the 

 coasts of southern California and western Mexico. 



Identification: The coloration is a unique gray to red or green crossed with 

 yellowish stripes and spots. Three prominent ridges run down the sides. 



Habits: This is a very inoffensive fish, so sluggish that it has been rammed 

 by boats on several occasions. Despite this, it can probably travel swiftly. The 

 feeding habits, teeth, and gill rakers are much Hke those of the basking shark. 

 It also basks on the surface and may school, though it is usually solitary. It 

 sometimes gulps plankton, small fish, or squids while standing vertically beneath 

 the school of food. 



THRESHER SHARKS: Family Alopidae 



These are large sharks with a large, extended upper tail lobe. Otherwise they 

 resemble mackerel sharks. 



