The jellies have a bad reputation. They knock out power plants, shut beaches, sink boats and wipe out fish stock.¹

They have no brain and just a thousand nerve cells. But scientists have discovered the Caribbean box jellyfish is smarter than it looks. It can learn to spot and avoid obstacles.

"For neuroscienceScience looking at the nervous system and the brain. ," says marine biologist Anders Garm, "this is pretty big news." The research helps us understand how memory is created and lost.

Sea jellies have existed for over 500 million years, longer than any other multi-organ animal. There are thousands of species, from microscopic gloop to the Lion's Mane, up to 36.5 metres long.

And some have remarkable abilities. During the polyp stage of their complex life cycle, they clone themselves into enormous jelly blooms. Polyps grow into jellyfish with a gelatinous bell and tentacles. But the so-called "immortal jellyfish" can turn back into a polyp and, in theory, live forever.

Some have lethal weapons. The Australian box jellyfish is the most venomous marine animal, and its stinging cells move faster than anything in the animal kingdom.

But jellyfish may also help us heal as they can repair themselves without scarring. Researchers use tentacle extract to stimulate cell growth, and believe it may be able to treat cancer.

And one jellyfish has even won a Nobel PrizeOne of a set of prizes, laid out in the will of Swedish chemist Alfred Nobel, given each year to people who "have conferred the greatest benefit to humankind". .² A special protein in Aequorea jellies makes them glow green. Scientists put this into human DNADeoxyribonucleic acid is the material in an organism that carries genetic information.. It made it possible to track genes and the movement of cells around the body. Expert Charles Mazel says its contribution to science is "incalculableToo great to be calculated or worked out. ".

But are jellyfish intelligent? They don't just float through life. They can learn, remember, and use their 24 eyes and hair-trigger sting cells to hunt their prey. Impressive for a brainless creature that is 95% water.

Scientists have discovered signs of intelligence in unexpected places, from fungal spores to the roots of trees. However, others argue that intelligence is a human superpower.

"Sitting on your shoulders is the most complicated object in the known universe," says theoretical physicist Michio Kaku. And this super brain allows us to ask important questions about the origins of intelligence.

Yes: Learning without a mind is a neat evolutionary trick. They have survived every mass extinction by keeping it simple, growing big without wasting energy on heavy-duty organs like brains.

No: This research confirms growing evidence that intelligence is widespread across the natural world. It is not extraordinary or a jelly superpower, but it is much older than previously thought.

Or... Sea jellies are not just one trick superheroes. They have deadly venom, self-healing skin, the ability to clone themselves and turn back the clock. They glow in the dark and have 360-degree vision.

Neuroscience - Science looking at the nervous system and the brain.

Nobel prize - One of a set of prizes, laid out in the will of Swedish chemist Alfred Nobel, given each year to people who "have conferred the greatest benefit to humankind".

DNA - Deoxyribonucleic acid is the material in an organism that carries genetic information.

Incalculable - Too great to be calculated or worked out.