These brainless jellyfish use their eyes and bundles of nerves to learn
For Caribbean box jellyfish, learning is literally a no-brainer.
In a new experiment, these animals learned to spot and avoid obstacles despite having no central brain, researchers report September 22 in Current Biology. This is the first evidence that jellyfish can make mental connections between events — such as seeing something and running into it — and change their behavior accordingly.
“Maybe learning does not need a very complex nervous system, but rather, learning is an integral part of nerve cells, or very limited circuitry,” says Jan Bielecki, a neuroethologist at Kiel University in Germany. If so, the new finding could help trace how learning evolved in animals.