An international team of scientists from the Universitat Autònoma de Barcelona (UAB) and those from the University of Stirling and the University of Bristol in the UK has published a finding in the Proceedings of the Royal Society of London detailing an experiment that showed fish might be able to experience emotions and even have consciousness - a UAB media report confirms.
The research team comprised of Sonia Rey, Simon Mackenzie, Reynaldo Vargas and Sebastian Boltaña of UAB's Institute of Biomedicine and Biotechnology; and Felicity Huntingford of Stirling and Toby Knowles of Bristol University.
Carrying out a number of tests on zebrafish, the researchers were able to establish increasing body temperature of 2-4 degrees in the fish when they were open to stress and marine situations that did not favor them. This is called emotional fever.
But some other researchers have never agreed that fish have consciousness or capable of experiencing emotions that could subject it to emotional fever. The dissident researchers agree that mammals, birds, and some reptiles could experience this phenomenon, but not fish.
The researchers divided 72 zebrafish into two equal groups of 36 each. One group was placed in a compartmentalized tank with temperatures ranging form18 to 35 degrees; and the second group which was used as the control was put in the tank compartment with only 28 degrees temperature.
The first group was restricted inside a net with the water temperature set to 27 degrees for a period of 15 minutes; and then released into other parts of the tank. This set of fish strived to go over and over to the compartment that has 28 degrees water temperature and the control group within this compartment did not make any attempt to leave this place.
The scientists interpreted this as emotional fever and based it on the ability of the stressed fish group to recall what they passed through and the location of the compartment with the unfavorable temperature, making them to go to the part with 28 degrees – while the control group in this place did not want to leave.
But other dissident scientists stand upon the fact that fish does not have cerebral cortex in its brain, incapable of learning or remembering anything, and cannot even experience suffering. But others would not agree to this position, stating that regardless of the simplicity of the fish’s brain structure, it is composed of features that can be compared to the hippocampus and amydala of vertebrates and mammals – the former is associated with spatial memory and learning while the former is linked to emotions.
"These findings are very interesting: expressing emotional fever suggests for the first time that fish have some degree of consciousness," noted Sonia Rey of the Institute of Aquaculture, University of Stirling and the UAB's Institute of Biomedicine and Biotechnology (IBB).