When it comes to feeding strategies, rabbitfish work as a team – one fish feeds while another other stands guard, a cooperative social behavior that was previously thought to be impossible for fish.

"These fishes literally watch each others' back," Dr. Simon Brandl from the ARC Centre of Excellence for Coral Reef Studies at James Cook University, said in a news release. "This behavior is so far unique among fishes and appears to be based on reciprocal cooperation between pair members."

When a pair of animals partakes in reciprocal cooperation, they are required to make an investment in their partner, with the expectation that the favor will be returned in the future. This behavior involves complex cognitive and social skills that fish weren't previously thought to have, according to the researchers.

"There has been a long standing debate about whether reciprocal cooperation can exist in animals that lack the highly developed cognitive and social skills found in humans and a few species of birds and primates." Dr. Brandl explained. "By showing that fishes – which are commonly considered to be cold, unsocial, and unintelligent – are capable of negotiating reciprocal cooperative systems, we provide evidence that cooperation may not be as exclusive as previously assumed."

Professor Bellwood, one of the study's co-authors from the Centre of Excellence for Coral Reef Studies, said that this study changes the perception scientists have of fish.

"Our findings should further ignite efforts to understand fishes as highly developed organisms with complex social behaviors," David Bellwood said in a statement. "This may also require a shift in how we study and ethically treat fishes."

Their study was recently published in the journal Scientific Reports

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