This fish does not have a cerebral cortex in its brain, but it behaves as it does
The human cerebral cortex, which is located in the outer layer of the brain, is involved in many high-level functions such as reasoning, emotion, intellect, memory, language, and social awareness.
Tropical bowfish (also known as spinnerfish) do not have a cerebral cortex, but to the surprise of researchers at the University of Haifa, this species shows prosocial behavior towards its “friends” and does not feel “cheated.”
The new study from the University of Haifa was published in the journal Communication biology Titled “Prosocial Behavior in Competitive Fishes: The Case of Archerfish,” I found that archerfish behave like animals that already have a cerebral cortex even though they do not have that part in their brains.
Archerfish: Using parts of the brain they don’t even have?
“It is clear that these social traits are important for survival in both cooperative and competitive societies, such as the fish we studied,” said Dr. Orit Nafsha, a postdoctoral student in social cognition and neuroscience from the University of Haifa who led the study. “Most of the time people operate in social contexts and depend on others for survival, so understanding the intentions and behavior of others is an important ability that allows us, as humans, to successfully survive in a social environment.”
They write that humans are social creatures, exhibit prosocial behaviors, and are sensitive to the actions of others and the rewards that result from them. “This social sensitivity has also been found in many other species, but not in all species. Research suggests that prosocial tendencies are most pronounced in naturally cooperative species whose social structure requires a high level of interdependence. Our study challenges this assumption By demonstrating that archer fish – competitive by nature – prefer targets that reward themselves and their tankmates, but only when the payoffs are equal. With no tankmate on the other side of the barrier, they showed no clear preference. Finding evidence of social behavior Positive and negative responses to unequal distribution of reward in favor of other fish suggest that in a competitive social environment, being social may be the most adaptive strategy for personal survival, even if it is beneficial to others as well.
According to the researchers, today’s research literature shows a bias to focus on engaging “higher” areas of the brain in the study of social behaviors. This neglects the potential contribution of developmentally developed subcortical areas at early stages.
Comparing fish cognition and behavior to those of primates faces several challenges, Navsha said. “Most studies have used different experimental manipulations and different dependent variables when studying non-primate animals. We specifically chose archer fish to serve as our model because of their remarkable ability to shoot down insects found on foliage above the water level. In this study, Nafsha, the research student, decided Dana Felker, Professor Simon Shamai-Tsouri, and Professor Shai Gabai from the Faculty of Psychological Sciences and the Institute for Information Processing and Decision Making at the University of Haifa, examined the evolutionary basis of social cooperation and social justice behaviors and how these behaviors are expressed in competitive species that lack a cortex.
They used a double aquarium divided into two parts by a transparent divider, with each side having an archer fish that could not pass from one side to the other, and each fish receiving food from its own side only. In the first experiment, the fish was given the opportunity to choose between a non-social target (the black starfish) on which it spat only received a reward, and a social target (the red starfish) on which the fish spit received food. In addition, other fish behind the barrier receive food. The colors were changed in the second phase of the experiment, with each color being used for a personal reward and a shared reward to avoid the alternative interpretation according to which the fish prefer a particular color and not necessarily a social behavior.
In both phases, all fish in the study always preferred the social goal, which was food for themselves and their buddy outside the glass. Finally, in the latest experiment, the researchers looked at what happens when a passive fish gets more food than an active fish. In this condition, the social target rewarded the spitter with one piece of food and the passive fish with two pieces of food, while the non-social target rewarded only the bowfish with one piece of food. At this point, the archer fish stops choosing the social target that would reward its friend the most.
The results of all experiments show that even fish in a competitive social environment will exhibit social behavior as long as the reward is equal but will stop doing so if the other fish gains more than them. “The study shows for the first time in laboratory conditions that the competitive archer fish behaves in a pro-social manner under certain conditions and stops behaving in this way when the product creates an unequal situation.
