Lovelorn fish turn gloomy when separated, study reveals (1/2)

This picture taken and released by the CNRS of the Bourgogne University shows a haplochromine cichlids (maylandia estherae) trying to open a box as part of a scientic experiment. Using a behavior test measuring the pessimism of the animal, researchers managed to show that a fish experiences "heartache" when separated from its partner. (Photo/Agencies)

This picture taken and released by the CNRS of the Bourgogne University shows a haplochromine cichlids (maylandia estherae) trying to open a box as part of a scientic experiment. Using a behavior test measuring the pessimism of the animal, researchers managed to show that a fish experiences "heartache" when separated from its partner. (Photo/Agencies)