Highly social birds and mammals are not the only animals looking out for each other — a new study shows that certain fish practice this behavior as well.

In a recent article published in the journal Scientific Reports, scientists from Australia's James Cook University share their findings on pairs of rabbitfish, which they found to cooperate and support each other during feeding.

Such behavior, previously not thought possible for fish, is similarly established among deeply social birds and mammals.

Study author Dr. Simon Brandl said that among rabbitfish pairs, one stays on guard while the other feeds, literally watching its partner's back.

This behavior, which appears to be unique among fish, is based on “reciprocal cooperation” — investing in a partner and later getting reciprocated, Brandl said. Reciprocal cooperation is believed to require complex cognitive and social skills, which has otherwise not been attributed to fish. 

"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," Brandl explained.

According to study co-author David Bellwood, the perception of fish as “cold scaly automatons” is gradually changing.

This research, Bellwood said, should help people understand fish as highly developed organisms with intricate social behaviors. He added that "this may also require a shift in how we study and ethically treat fishes."

Photo: Elias Levy | Flickr