Researchers from the Agency of Science, Technology and Research in Singapore have analysed the nature of the “alarm substance” which causes a school of fish to disperse in fear when one member of the school is injured.
The researchers have shown that one chemical component of the substance is a sugar called chondroitin sulfate, found in abundance in the skin of the fish. When a fish is injured, the sugars break down and fragments are scattered throughout the school, causing the fear response.
The new findings help to explain how such a mechanism could evolve despite its providing no benefit to the injured fish.
Read more at Agency of Science, Technology and Research