Reciprocal cooperation, meaning an investment in a partner, which is later reciprocated, is thought to require complex cognitive and social skills. While such behavior has been documented for highly social mammals and birds, it has previously been believed to be an impossible task for fishes.
Researchers from the ARC Center of Excellence for Coral Reef Studies at James Cook University study have found that pairs of rabbitfishes cooperate and support each other while feeding.
Researcher Simon Brandl said, "We found that rabbitfish pairs coordinate their vigilance activity quite strictly, thereby providing safety for their foraging partner. In other words, one partner stays 'on guard' while the other feeds - these fishes literally watch each others' back. This behavior is so far unique among fishes and appears to be based on reciprocal cooperation between pair members."
Brandl further added that their research shows clear coordination and presents intriguing evidence for reciprocal cooperation between the rabbitfish pairs. Co-author Bellwood said, "The findings should further ignite efforts to understand fishes as highly developed organisms with complex social behaviors."