Fish "Scary Stuff" Alarm Call Deciphered

In the 1930s, the Austrian biologist Karl von Frisch, of waggle-dancing honey bee fame, performed some little-known experiments on dancing minnows. The fish weren’t dancing for fun.Von Frisch showed that when a minnow’s skin cells are damaged, as happens during a predator attack, the fish releases a chemical into the water that triggers nearby fish to flee. Von Frisch called the chemical “Schreckstoff,” German for “scary stuff,” and yesterday, scientists described its chemical makeup.The research team first separated the skin mucous of zebrafish into its different chemical components and then tested how each affects the behavior of a group of fish in a tank. One of the chemicals, a sugar called chondroitin sulfate, caused a dramatic fear response.Read more (and watch the video!) at...Smithsonian's Surprising Science, February 2012.