Jellyfish show how you don’t need a brain to learn, say researchers

Caribbean box jellyfish were placed in differently decorated tanks and their collisions with the walls were observed over time. Photograph: Jan Bielecki

Jellyfish change their behaviour based on past experiences, researchers have revealed, in a study that suggests learning could be a fundamental property of the way nerve cells work.

Unlike humans, jellyfish do not have a central brain. However, box jellyfish have clusters of neurons associated with the creatures’ eye-like structures, known as rhopalia, with this system – known as rhopalia – acting as visual information processing centres.