Curious Jellyfish Open New Avenues for Nervous System Research
05.11.2025
A team of researchers from the University of Padua and the University of Trieste has observed surprising behaviors in jellyfish of the species Aurelia (moon jellyfish). The study, published in «Behavioral and Brain Sciences», explores the origin of curiosity and the possibility of cognition without a centralized brain.
Cinzia Chiandetti, a professor of Cognitive Neuroscience at the Department of Life Sciences at the University of Trieste, highlights that despite the radial nervous system and rudimentary sensory organs of jellyfish, signs of memory and attraction to novelty were found. "Our results are particularly interesting," explains Cinzia Chiandetti, "because these animals are considered 'brainless': their nervous system is organized in a radial manner, without a command center, and equipped only with rudimentary sensory organs. Finding signs of memory and attraction to novelty in them is an important key to understanding the evolution of nervous systems and cognition itself."
Experiments with young jellyfish in a tank showed that these animals remember an object and prefer a new one, a behavior known as "neophilia." Christian Agrillo, a professor of Comparative Psychology at the University of Padua, specifies that jellyfish retain information in memory for at least a minute, suggesting they might approach humans out of curiosity. "Not only did the jellyfish show neophilia," comments Christian Agrillo, "but they also demonstrated the ability to retain specific information in memory for at least a minute. We generally think that in the sea they approach us passively, carried by the current. Our study also opens up the possibility that in some cases they do so out of the same attraction to novelty documented here. One could say they might be curious to get to know us!"
The study invites a reconsideration of traditional models that link cognition to the presence of centralized brains, suggesting that even "diffuse" nervous systems, like those of jellyfish, can support complex behaviors. A discovery that once again pushes the boundaries of what we think is possible in the animal world.
