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Shark and Company 



An Electric ray ( Torpedo nobiliana ) . 



Courtesy, Harvard Museum of Comparative Zoology 



In an experiment to determine how the Torpedo uses its electric 

 organ to stun prey, Dr. D. P. Wilson of the Plymouth Aquarium in 

 England connected electrodes to a dead 9-inch Horse mackerel, which 

 was pulled through an aquarium tank past a Torpedo nobiliana. The 

 Torpedo pounced on the fish. As it enfolded the mackerel with its 

 pectorals, the electrodes detected a strong shock. If the mackerel had 

 been alive, presumably this shock would have been sufficient to render 

 it helpless while the Torpedo devoured it. 



One type of Electric ray, the Blind Torpedo ray (Typhlonarke 

 aysoni Hamilton, 1902), has no eyes. It makes its way along the sea 

 bottom around New Zealand on modified ventral fins that, in a weird 

 way, resemble stumpy legs. The fins project at right angles to the body 

 and their tips are covered with a thick skin. These "fins" are far better 

 for moving over the ocean bed than for swimming through the sea. 



A species similar to T. nobiliana (Torpedo calif ornica Ay res, 1855) 

 is found along the Pacific Coast of North America, from southern British 

 Columbia to southern California. 



