English: The “electric image” of the external environment is determined by the conductive properties of surrounding objects. The electric field emanates from the electric organ in the tail region (gray rectangle) and is sensed by the electroreceptive skin areas, using two electric “foveas” to actively search and inspect objects. Shown are the field distortions created by two different types of objects: a plant that conducts better than water, above (green) and a non-conducting stone, below (gray). Based on: Heiligenberg, Walter (1977) Principles of Electrolocation and Jamming Avoidance in Electric Fish: A Neuroethological Approach Springer-Verlag. ISBN 9780387083674.