Box jellyfish, despite being brainless, have been found to have the ability to learn, according to a study published in Current Biology. The researchers focused on a behavioral trait in box jellies where they execute a swift turn when approaching a mangrove root in order to avoid a collision. By training the box jellies in a lab environment, the researchers discovered that they were able to learn from collisions and adjust their behavior accordingly. Additionally, when the visual neurons of the box jellyfish were removed and studied in a dish, they still showed signs of learning. This suggests that learning may exist outside of the brain. The study provides insights into the evolution of learning and raises questions about the duration of box jellyfish’s memory.
https://www.nytimes.com/2023/09/22/science/jellyfish-learning-neurons.html