Mosquito fish don’t just count on each other for protection from predators — they literally count each other for such protection. These guppylike fish can use numerical information to identify the larger of tw
o nearby groups of fellow fish, report psychologist Marco Dadda of the University of Padova in Italy and his colleagues in an upcoming Cognition.That’s a useful skill to have, the researchers say. Larger groups, or shoals, offer a more effective shield against bigger fish with empty bellies.The researchers allowed individual mosquitofish in a tank to see groups of other fish, but barricades prevented them from seeing an entire group at once. When viewing fish one at a time in each of two groups, mosquito fish spent much more time near larger groups, Dadda and his colleagues report. The fish preferred groups of three over two fish and groups with eight fish over four fish.“We have provided the first evidence that fish are capable of selecting the larger group of social companions by relying exclusively on numerical information,” Dadda says.
o nearby groups of fellow fish, report psychologist Marco Dadda of the University of Padova in Italy and his colleagues in an upcoming Cognition.That’s a useful skill to have, the researchers say. Larger groups, or shoals, offer a more effective shield against bigger fish with empty bellies.The researchers allowed individual mosquitofish in a tank to see groups of other fish, but barricades prevented them from seeing an entire group at once. When viewing fish one at a time in each of two groups, mosquito fish spent much more time near larger groups, Dadda and his colleagues report. The fish preferred groups of three over two fish and groups with eight fish over four fish.“We have provided the first evidence that fish are capable of selecting the larger group of social companions by relying exclusively on numerical information,” Dadda says.For further details visit at : www.sciencenews.org/view/generic/id/44844/title/Mosquito_fish_count_comrades_to_stay_alive
