Hard to understand! Scientists discover that jellyfish can learn from past experiences – even though they don’t have a brain

Because jellyfish are stinging, mindless blobs, many may assume they are worlds apart from humans.

But scientists now suspect that these wobbly creatures are more like us than we first thought, thanks to their incredible ability to learn from past experiences.

No larger than a fingernail, the Caribbean box jellyfish has a complex visual system of 24 eyes that allows them to detect obstacles when navigating mangrove habitats.

The groundbreaking discovery, revealed by the University of Copenhagen, challenges previous ideas that centralized brains are essential for processing complex thoughts in animals.

“It is surprising how quickly these animals learn; “It’s about the same pace as advanced animals,” said Associate Professor Anders Garm.

Scientists claim they have managed to teach a jellyfish to recognize and avoid obstacles

“Even the simplest nervous system appears to be capable of advanced learning, and this may be an extremely fundamental cellular mechanism that was invented early in the evolution of the nervous system.”

Caribbean box jellyfish – or Tripedalia cystophora – are tiny creatures that thrive in warm tropical waters.

While the sting of many species of box jellyfish is fatal to humans, the Caribbean species only causes pain for a few days.

As part of the latest research, published in Current Biology, experts wanted to investigate whether the jellyfish can undergo “associative learning.”

This refers to the process by which organisms create mental connections and sensory stimuli.

For humans, for example, this could be a reminder that hot ovens are dangerous and painful to touch.

To test this using a jellyfish, scientists decorated a round tank with gray and white stripes to simulate its natural habitat.

In this case, the gray stripes mimicked “faraway” mangrove roots from the jellyfish’s perspective.

Initially, the scientists observed the fish encountering these “distant streaks” quite frequently, but that seemed to change after a period of 7.5 minutes.

Caribbean box jellyfish – or Tripedalia cystophora – are tiny creatures that thrive in warm tropical waters

The jellyfish study challenges previous ideas that complex learning requires a brain

As part of the latest research, published in Current Biology, experts wanted to investigate whether the jellyfish can undergo “associative learning.”

By then, the fish increased its average distance from the wall by about 50 percent and the fish’s contact with the wall decreased by half.

Scientists believe this is due to the species’ visual sensory centers, called “rhopalia.”

Each of these unusual structures controls the jellyfish’s pulsating movement, which increases in frequency as it avoids obstacles.

With this in mind, the team now hopes to delve deeper into a jellyfish’s mind and better understand its ability to form memories.

“If you want to understand complex structures, it is always good to start as simple as possible,” added Professor Garm.

“If we look at these relatively simple nervous systems in jellyfish, we have a much higher chance of understanding all the details and how they work together to carry out behaviors.”