This picture attempts to show the relationship between the electrical perceptions of
a fish and its actual surroundings. Each of the items on the left gives information
about the item on the right. "Location on body" refers to which receptors on the
fish received the information. Amplitude refers to the strength of the signal the
fish received. Phase and shape describe the form of the wave of electricity
(visible by oscilloscope). On the right, angular position is the position of the
object with relationship to where the fish is (at what point on the "clock" if the
fish is at the center). Distance and size are self-explanatory. Conductivity is
whether the object conducts electricity, while dielectric constant is the degree to
which it does so. And shape, too, is fairly self-explanatory.
Magnitudes of electric images are strongly dependent on object distance because of
the rapid attenuation of the fish's electric field with distance from its body
This picture shows a graph of the field of an electric fish. Note that the field
is strongest near the tail and rapidly weakens as the distance from the fish
increases. This gives a fairly accurate sense of distance, if not an exact shape
impression.
The undisturbed field of a fish (middle) and how it is shifted with a
nonconductive sphere (right). The sphere reflects the field back to the fish, where
it senses the reflected field through receptors in the skin. The red color represents
the strongest field.
