Trivia from NEW SCIENTIST, April 22-28, 2006 page 45.
Bluegill sunfish (Lepomis macrochirus) have been recruited by US army researchers to detect chemical attacks on drinking water. The fish respond to toxins in water by breathing faster and deeper, coughing more often and moving in a characteristic way. These movements generate electrical signals that are picked up by electrodes and sent to a computer. When the number of fish showing signs of stress passes a certain threshold, the computer sounds an alarm. The system is in use at a New York City reservoir.
