By Annie Palmer For Dailymail.com
Published: 01:55 BST, 12 June 2019 | Updated: 01:55 BST, 12 June 2019
Humans aren't the only species whose mental state is affected when they lose their lover.
Female cichlids, a type of monogamous fish that primarily dwells in South America, become depressed and lovesick when their mate is removed and they're placed with a non-preferred male partner, a new study has found.
Researchers came to this conclusion after the female fish took longer to investigate boxes that either contained food or were empty, demonstrating symptoms of apathy.
Female cichlids, a type of fish that primarily dwells in South America, become depressed and lovesick when their mate is removed and they're placed with a non-preferred male partner
In what's believed to be a first-of-its-kind study, researchers say they've determined fish can form attachments to sexual partners.
Through a series of cognitive tests, they found that female fish were more likely to take on a 'glass half-full' mental state when they remained with their chosen partners.
In addition, they spawned more quickly and tended to their eggs more often.
The study, published Tuesday in the journal Proceedings of the Royal Society B, was conducted by researchers from the University of Burgundy in Dijon, France.
It's also believed to be the first study that shows non-human species can also form attachments to sexual partners.
'It is, as far as we know, the very first demonstration of emotional bonds between partners in non-human species,' Francois-Xavier Dechaume-Moncharmont, one of the study's co-authors, told Inside Science.
In order to prove this hypothesis, the researchers carried out a series of cognitive tests in a group of 33 female cichlids.
Over the course of two weeks, they closely studied how the female fish behaviors changed when they were paired with a male fish that they had not picked themselves.
When females were paired up with a male fish