‘Cyborg Jellyfish’ could transform ocean research, study finds

In a dark laboratory at the University of Colorado Boulder, soft pulses of light dance across the surface of a large aquarium. Inside, moon jellyfish move in slow, hypnotic patterns. Their clear, bell-shaped bodies expand and contract like floating parachutes. Neon reflections flicker along their delicate tentacles as they drift silently through the water.

These are no ordinary jellyfish. Under the care of mechanical engineer Nicole Xu and her team, these creatures are being turned into something new: living ocean explorers. They’ve been fitted with tiny electronic devices that help researchers guide their movements, turning them into “cyborg jellyfish.” With this innovation, jellyfish could soon swim to places in the ocean that humans and even machines struggle to reach.

Xu, an assistant professor in CU Boulder’s Paul M. Rady Department of Mechanical Engineering, has been captivated by jellyfish since she was a student. “There’s really something special about the way moon jellies swim,” she said. “We want to unlock that to create more energy-efficient, next-generation underwater vehicles.”

That dream is starting to take shape. Xu’s modified jellyfish can be guided by devices that work similarly to a pacemaker. The tool sends small pulses to the jellyfish’s muscles, gently nudging them in a chosen direction. These pulses trigger contractions in their bodies, the same way natural swimming occurs. “We’re stimulating the swim muscle by causing contractions and turning the animals toward a certain direction,” Xu explained.

This simple trick has powerful potential. In the future, these enhanced jellyfish could carry sensors through hard-to-reach parts of the ocean, gathering real-time data on temperature, acidity, and other key markers of ocean health. They could help scientists track how climate change is affecting marine ecosystems—all without the need for bulky, costly machines.

The ocean covers over 70% of Earth’s surface, yet much of it remains unexplored. Studying its depths requires equipment that is often expensive, heavy, and hard to transport. For example, some remote areas like the Mariana Trench, nearly 36,000 feet deep, are rarely visited by even the most advanced research subs.

Jellyfish, however, are already there. These ancient creatures have roamed the seas for over 500 million years. They exist across oceans and at all depths, from surface waters to the darkest, coldest zones of the deep sea. Their evolutionary design has changed very little over time, and for good reason—it works.

Moon jellies, known scientifically as Aurelia aurita, are among the most energy-efficient animals ever studied. Despite lacking a brain or spine, they can navigate, hunt, and survive using two overlapping nerve nets and a network of simple sensory organs. They don’t have nociceptors, which are the pain receptors found in humans and other animals. That means they can’t feel pain the way we do—a fact that makes ethical experimentation with them less controversial.

They also don’t sting humans in harmful ways. Though they use their tentacles to catch small prey like zooplankton and tiny fish, their sting cells aren’t strong enough to pierce human skin.

Moon jellies range widely in size—from just over a centimeter to more than a foot in diameter. They glide through the water by pulsing their bell-like bodies. This natural motion doesn’t just look beautiful—it’s also incredibly efficient. Xu and her team believe there’s much we can learn from it. “We want to mimic that movement to improve how we design underwater vehicles,” she said.

About five years ago, Xu and her former academic advisor started developing the idea of biohybrid robotic jellyfish. In 2020, they tested the early versions in shallow ocean waters near Woods Hole, Massachusetts. By gently steering the jellyfish, the team was able to control their path through the water—an important step toward creating a natural, low-impact tool for marine science.

To understand how moon jellyfish move so gracefully, Xu and her team study the flow of water around them. Recently, they developed a new method that uses biodegradable particles to visualize those movements. Rather than using traditional tracers like silver-coated glass beads—which are not eco-friendly—they used corn starch particles suspended in the tank’s water. A laser beam shone through the tank revealed the swirling flow patterns created by the jellyfish’s gentle pulses.

This method is not only safer for marine environments, it’s also cheaper and more sustainable. The results were published by Xu, research associate Yunxing Su, and graduate student Mija Jovchevska. Their study, published in the journal, Physical Review Fluids, showed that natural particles can be just as effective for tracking water flow as synthetic ones, while reducing harm to the ocean.

Meanwhile, Xu continues to refine the steering systems for jellyfish. Graduate student Charlie Fraga is helping to improve how the microelectronic devices work in the wild. One of their goals is to develop tools that allow scientists to control jellyfish with greater accuracy over long distances. Xu also plans to add tiny environmental sensors, turning each jellyfish into a miniature ocean lab.

By using jellyfish instead of underwater drones, scientists can study sensitive areas without disturbing marine life. These soft-bodied swimmers don’t require batteries or fuel. They move naturally with the ocean’s flow, leaving almost no footprint behind.

But with innovation comes responsibility. That’s why Xu and her team are also exploring the ethics of working with invertebrates. Although moon jellies lack a brain and pain receptors, there’s increasing evidence that some invertebrates may still react to harmful conditions in ways we don’t yet fully understand.

In a recent paper, Xu joined other scientists in calling for more thoughtful research practices when working with creatures like jellyfish. It’s easy to assume that invertebrates don’t suffer, but new studies suggest that’s not always the case. Some species show signs of stress when exposed to unpleasant stimuli. That makes it important to monitor behavior and make sure research methods are safe and humane.

In her lab, Xu pays close attention to the health of her jellyfish. One sign of stress is excess mucus production. Another is reduced reproduction. So far, her jellies show none of those signs. In fact, her tanks are filled with baby polyps—tiny young jellyfish no larger than a pinhead, slowly developing their tentacles. That’s a strong indication that the animals are thriving.

“It’s our responsibility as researchers to think about these ethical considerations up front,” Xu said. “But as far as we can tell, the jellyfish are doing well. They’re thriving.”

Xu’s lab now includes a small team of graduate students and research staff. Together, they’re shaping the future of ocean research. By blending biology, technology, and environmental ethics, they’re building tools that could one day help scientists monitor coral reefs, study deep sea vents, or measure changes in water chemistry due to climate change.

The dream is not just to use jellyfish, but to learn from them. Their natural elegance may hold the key to designing energy-saving underwater vehicles. Their ability to survive in the harshest ocean conditions may inspire new tools for conservation. And their quiet presence, swimming gently under the glow of lab lights, reminds us that nature often provides the best blueprint of all.

Note: The article above provided above by The Brighter Side of News.

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