Nature has published a paper that illuminates the complex nature of relationships among fishes. A study carried out around Lizard Island, Greta Barrier Reef, Australia has shown that rabbitfishes (Siganus corallinus, S. doliatus, S. puellus, and S. vulpinus) operate as pairs, with one partner maintaining a look-out while the other feeds. behavior suggests that the fish have powers of cognition, reciprocity and cooperation that were previously not associated with fishes in general.