"Long before it's in the papers"
September 25, 2015


Some fish found to “stand on lookout” for each other

Sept. 25, 2015
Courtesy of James Cook University
and World Science staff

Some fish will co­op­er­ate to act as look­outs for each oth­er—one of them watch­ing for preda­tors while the oth­er has its back turned and eats, ac­cord­ing to a new stu­dy.

Such be­hav­ior had been doc­u­mented for highly so­cial birds and mam­mals, but fish were con­sid­ered—in a word—too dumb to do it.

Rabbitfish said to be cooperating. (Credit: Jordan Casey)

The find­ing may “re­quire a shift in how we study and eth­ic­ally treat fish­es,” said study col­la­bo­ra­tor Da­vid Bell­wood of James Cook Un­ivers­ity in Aus­tral­ia.

Bell­wood and co-re­searcher Si­mon Brandl, al­so of the uni­vers­ity, said they noted the be­hav­ior among rab­bit­fish­es, brightly col­ored plant- and algae-eaters from the trop­i­cal Pa­cif­ic and In­di­an oceans.

They “lit­erally watch each oth­ers’ back,” said Brandl. They “co­or­di­nate their vig­i­lance ac­ti­vity quite strict­ly.” 

The activity is truly “re­cip­ro­cal,” as co­op­er­at­ing pairs even­tu­ally switch places in the feed-and-guard du­ty, the re­search­ers added.

“There has been a long­stand­ing 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.”

Our per­cep­tion of fish­es as cold, scaly au­toma­tons is slowly chang­ing, added Bell­wood. “Our find­ings should fur­ther ig­nite ef­forts to un­der­stand fish­es as highly de­vel­oped or­gan­isms with com­plex so­cial be­hav­iors.”

The find­ings are pub­lished in the re­search jour­nal Na­ture Sci­en­tif­ic Re­ports.

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Some fish will cooperate to act as lookouts for each other—one of them watching for predators whilst the other eats, according to a new study. Such behavior has been documented for highly social birds and mammals, but fish were considered—in a word—too dumb to do it. The finding may “require a shift in how we study and ethically treat fishes,” said study collaborator David Bellwood of James Cook University in Australia. Bellwood and co-researcher Simon Brandl, also of the university, observed the behavior among rabbitfishes, brightly colored plant- and algae-eaters from the tropical Pacific and Indian oceans. They “literally watch each others’ back,” said Brandl. They “coordinate their vigilance activity quite strictly.” The behavior is truly “reciprocal,” as cooperating pairs eventually switch places in the feed-and-guard duty, the researchers added. “There has been a longstanding 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.” Our perception of fishes as cold, scaly automatons is slowly changing, added Bellwood. “Our findings should further ignite efforts to understand fishes as highly developed organisms with complex social behaviors.” The findings are published in the research journal Nature Scientific Reports