Lifestyle & Belief

New study finds fish cultivate reputations to enhance foraging success


A rockmover wrasse, a close relative of Labroides dimidiatus, swims in an aquarium in Berlin. Scientists say certain types of wrasse value their reputations to improve their foraging returns.


Sean Gallup

George Washington once said that a person who values their reputation knows that it is "better to be alone than in bad company."

Washington could well have said the same thing about fish, according to a new study by scientists from the University of Queensland, the University of Cambridge and the University of Neuchatel.

Research has shown that it's not just people who value a good reputation and care what others think of them; fish do too.

A type of cleaner wrasse (Labroides dimidiatus), one of those stripy finger-sized fish that eat parasites and dead flesh off larger fish on coral reefs, know all about the importance of keeping good company.

Their customers judge them, and they are judged by their peers, based on how well they resist the temptation to bite off a little more than their customer is offering.

Published last week in Current Biology, the study shows that other large reef fish that observe greedy behavior avoid those cleaner fish with a reputation for biting.

UQ's Dr. Lexa Grutter said the research showed for the first time that having an audience can influence levels of cooperation in a non-human animal.

"Having an audience makes cleaner fish work to improve their reputation by behaving more cooperatively," Dr. Grutter said.

"The fish in the audience -- what we call ‘eavesdropping bystanders' -- used image scoring to decide which cleaner fish to avoid."

The wrasse "immediately increase" their levels of cooperation in the presence of bystander client reef fish, said the study, which is available online.

"Furthermore, we find that bystanders respond to any occurrence of cleaners cheating their current client with avoidance," it said.