Electroreception and magnetoreception in simple and complex organisms.

A considerable body of evidence now indicates that electromagnetic and geomagnetic detection systems exist in both simple, unicellular organisms and in more complex species such as avians, bees, and marine animals. A major challenge that faces researchers in this field is the identification of physiological mechanisms through which the detection of weak fields provides significant somatosensory cues for direction finding, foraging, and predation. Many of the anatomical, physiological, and biophysical approaches that are being taken in studies of this nature are described in the series of review articles that appear in this issue of Bioelectromagnetics.