Fish are not generally known for having strong personalities or bonds, but new research suggests Rabbitfish have each other's backs.

Scientists determined that Rabbitfish pairs will cooperate with and support each other during feeding, James Cook University reported. This type of behavior has been observed among birds and other animals, but it was previously believed to be impossible for fish.

"We found that rabbitfish pairs coordinate their vigilance activity quite strictly, thereby providing safety for their foraging partner," said Simon Brandl from the ARC Centre of Excellence for Coral Reef Studies. "In other words, one partner stays 'on guard' while the other feeds - these fishes literally watch each other's back. This [behavior] is so far unique among fishes and appears to be based on reciprocal cooperation between pair members."

Reciprocal cooperation requires investment in a partner as well as complex cognitive and social skills; these qualities were not believed to be present in fish. This new research demonstrated that fish can exhibit "clear coordination."

"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," Brandl said. "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."

The new findings could prove that fish are highly developed organisms capable of complex social behaviors.

"This may also require a shift in how we study and ethically treat fishes," concluded co-author, Professor Bellwood, also from the Centre of Excellence for Coral Reef Studies.

The findings were published in a recent edition of the journal Nature Scientific Reports.