Although it’s speculated that every animal has some sort of consciousness, certain animals are thought to be limited in their emotional abilities. Consciousness and emotions have been well-documented in different kinds of animals, such as mammals, birds, and even a variety of reptiles.
For the first time, however, emotions have been documented in fish by tracking a phenomenon known as emotional fever, which is a state where the body temperature can change a couple of degrees in certain situations as the body becomes more alert to certain senses.
It has never been documented in fish before, but in a recent study involving a group of 72 zebra fish performed by researchers from the University of Barcelona, University of Stirling, and University of Bristol, it has been found that when placed in stressful situations, even fish display qualities of emotional fever, which illustrates that fish too feel emotions depending on the situation at hand.
The 72 zebra fish were separated into two groups of 36 – a control group and a test group. The control group were allowed to roam freely in a comfortable tank of water measured at 28º Celsius, while the test group were trapped inside a net in waters of 27º Celsius for 15 minutes before being allowed to roam freely through the tank of water, which ranged from 18º Celsius to 35º Celsius.
The fish that were subjected to the stressful net situation were found swimming away from the 27º Celsius region of the water to search for regions of higher temperatures, indicating that they were attempting to increase their body temperature by up to 4º Celsius and were displaying signs of emotional fever.
Because fish were once thought to be simple creatures without any kind of consciousness or emotional senses, this is a breakthrough in the understanding of fish’s minds. It shows that despite the simplicity of their brains, they might just be able to experience feelings after all.
Source: The Royal Society Publishing
