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Fish Alarms

November 3, 2015

Damselfish attract multiple predators with a chemical cue, giving themselves a way to escape.


Figure 2

A lemon damselfish hovering over its coral shelter while looking for predators. (Oona Lönnstedt)


Fish alarms. I’m Bob Hirshon and this is Science Update.

Small lemon damselfish are a favorite snack for all kinds of predators in Australia’s Great Barrier Reef.

OONA LÖNNSTEDT (Uppsala University):

They’re sort of t like the M&Ms of the reef, everything eats them.


That’s Uppsala University marine biologist Oona Lönnstedt. She says when bitten, damselfish skin emits a chemical alarm signal into the water, attracting even more predators to the scene. But this actually helps the damselfish get away, Lönnstedt and her colleagues at James Cook University report in the Proceedings of the Royal Society B.

LÖNNSTEDT (Uppsala University):

The predators will start fighting with the primary predator over the prey and that means that the prey has a chance to escape.


In one experiment, the plucky fish dodged near-certain fate nearly 40% of the time when more predators were summoned, demonstrating the importance of the chemical cue to survival. I’m Bob Hirshon, for AAAS, the science society.