Electric Rays: a Shocking Use of The electric rays (order
Torpediniformes) have fascinated naturalists since antiquity,
being best known for their highly specialized electrogenic
organs. These organs are generally kidney-shaped, composed of
stacks of 500 to over 1 000 striated muscle plaques that have
been modified from the gill musculature. These plaques are all
enervated on the same side, so that the electricity generated
via muscular contraction is summed to produce an external shock.
Voltage potentials recorded from different electric rays vary
tremendously, having been measured at as little as 8 to 37 volts
(narcinids) up to 220 volts (in the torpedinid Torpedo
nobiliana). The result is a jolt of electricity ranging from
moderately tingly to stunningly powerful. In some forms, the
shock is directed upward — where it may serve to deter would-be
predators — and in others downward — where it may be used to
incapacitate prey. Recent field research carried out by Chris
Lowe, Dick Bray, and Don Nelson off sout