date:Jul 12, 2012
released when a fish is physically damaged, alerting nearby fish to the predator's presence.
In her experiments, conducted in a four-foot-diameter tank, fish that weren't exposed to copper would freeze in the presence of Schreckstoff, making it harder for motion-sensitive predators to detect them. On average, half a minute would go by before they were attacked.
But salmon in water with just five parts of copper per billion failed to detect the Schreckstoff and kept swimming. They were attacke