"A Novel Electrosensory Organ" is depicted on the cover of BioScience (May 2007, now on display with this week's journals) in the form of the rostrum of the paddlefish Polyodon spathula. Take a few moments away from studying for finals and marvel at the evolutionary pathway that led to the development of this exquisitely receptive organ, uniquely adapted to detect planktonic prey (primarily the water flea, Daphnia) in turbid, vision-limiting environments.
Investigators Lon Wilkens and Michael Hofmann, Center for Neurodynamics and the Department of Biology, Univ. of Missouri St. Louis, have studied P. spathula for more than a dozen years. See also an earlier review by Wilkens in The senses of fish : adaptations for the reception of natural stimuli edited by Gerhard von der Emde, Joachim Mogdans, and B.G. Kapoor [Science Library QL639.1 .S44 2004].