SHARK SENSORY
ELECTRORECEPTION
  • Ability to detect the smallest of electric fields
  • The shark’s body acts as a dipole (one positive end, one negative end) and thus produces an electric field 
  • Electric fields are perceived by fragile, jelly-filled electroreceptors called ‘ampullae of Lorenzini’ 
  • When an alien field approaches within a few meters of the shark, it distorts this field thus allowing the shark to sense things it might not otherwise be able to see, hear or smell 
  • This ability to sense weak electrical voltages, as low as 0.005 microvolts per centimeter, also allows sharks to navigate with the earth’s magnetic field
Field distortion due to presence of fish
Drawing by Chris Moles (cmoles@chat.carleton.ca)

bharris@chat.carleton.ca