Researchers recently discovered that when damselfish are caught by predators, they release a chemical “distress call” that boosts their chances of survival.
It’s long been known that fish contain a chemical in their skin that is release when they are injured. The chemical triggers “fearful and escape behavior in nearby fish,” but until now, researchers didn’t understand the benefit this response has for the injured fish.
“For decades scientists have debated the evolutionary origin of chemical alarm cues in fish,” lead author, Dr. Oona Lönnstedt, now a research fellow at the University of Uppsala, explained in a news release.
Dr. Lönnstedt and other researchers at the ARC Centre of Excellence for Coral Reef Studies (Coral CoE) at James Cook University determined that the chemical cue actually attracts more predators.
“More predators would seem to mean more trouble, but we discovered that additional predators interfere with the initial predation event, allowing the prey a greater chance to escape,” said study co-author Professor Mark McCormick from the Coral CoE.
“When caught by a predator, small damselfish have almost no chance of escaping their fate as the predator’s next meal. However, when another fish predator is attracted to the capture site, prey will escape about 40 percent of the time.”
This is because when more predators arrive, they will typically begin fighting over the prey, giving it more opportunities to swim away.
“It all goes to show that coral reef fish have evolved quite a range of clever strategies for survival which are deployed when a threatening situation demands,” Dr. Lönnstedt said.
To learn more:
- Read the Coral CoE news release: Distressed damsels cry for help
- Read the full study: Damsel in distress: captured damselfish prey emit chemical cues that attract secondary predators and improve escape chances
Copyright © 2015 by Marine Science Today, a publication of Marine Science Today LLC.