TIGERS OF THE DEEP 



Wiedersheim and Parker have stated : ''The side of the 

 electric plate on which the nerve branches out is negative 

 at the moment of discharge, while the opposite side is 

 positive." (This refers to each disc in the structure.) 

 "From the different arrangements of the parts the electric 

 shock passes in different directions in the three fishes. 

 In Malapterurus (the catfish) from the head to the tail; 

 in Gymnotus (the electric eel) in the contrary direction ; in 

 the torpedo from below upwards." 



The organ's activity is entirely dependent upon two 

 factors — the nerve stimulus from the brain of the creature, 

 when it wills to send out an electrical discharge, and a 

 certain degree of freshness in the structure itself If the 

 nerve connections with the brain are severed there can 

 be no discharge — showing that it is not just a "battery". 

 Also, if the animal is tired, or there have been repeated 

 discharges, the power to produce the current temporarily 

 ceases. 



It is a remarkable fact that the torpedo, gifted with 

 such exceptional power among fishes, should have one 

 tiny foe which is quite insensible to electric shocks. This 

 is the Branchellion, a parasitic creature classified with the 

 Hirudinea (leeches), which generally measures from an 

 inch to an inch and a half in length. It clings to the 

 torpedo and feeds upon its juices, yet remains completely 

 indifferent to its host's electrical discharges. The currents 

 must pass through this tiny creature's body, yet dis- 

 charges which are enough to kill fishes thousands 

 of times larger than Branchellion leave it quite un- 

 harmed. 



The remora, or sucking-fish — a popular name for any 

 species of the family Echineididae and order Discocephali — 

 is a parasitic fish of a different kind, averaging two feet in 

 length, which specializes in its attachments to various 

 creatures larger than itself. Some confine themselves to 

 dolphins, some to swordfish, and so on. The common 

 species on the Atlantic coast of the United States is the 



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