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Mantis Shrimp

Common Name: Mantis shrimp Scientific Name: Stomatopoda Size: Up to 16 inches long Weight: Around 1.5 pounds What are mantis shrimp?

Despite their name, mantis shrimp are not true shrimp but a type of stomatopod: a relative of crabs and lobsters that has been on Earth for over 400 million years. There are more than 400 different species of mantis shrimp.

Peacock mantis shrimp—also called harlequin or painted mantis shrimp—are arguably the best-known of the family. These critters get their name from their kaleidoscope shell—like a peacock's tail—and their hinged forearms which resemble that of a praying mantis and are kept tucked away until the moment of attack. These solitary, aggressive animals are famous for their ferocious punch—as fast as a bullet and strong enough to snap a crab's claw.

Habitat and appearance

Mantis shrimp live in warm, shallow waters in the Indian and Pacific oceans. To build a home, they use their raptor-like front arm to dig burrows on the seabed surrounding a coral reef. When they move on, other marine animals may take up residence in the abandoned burrow.

Growing to around the length of a butter knife, peacock mantis shrimp have rainbow shells—usually blue, green, and yellow—and red legs. Their purple eyes sit on top of stalks above their head and can move independently of one other for a better view.

(Learn about the peacock mantis shrimp with your kids.)

Not all mantis shrimp boast these spectacular colors. Zebra mantis shrimp—the largest of all the species—are named for their cream and brown stripes, while Red Sea mantis shrimp are beige with thin red stripes and a dark rear end.

But all these animals are best known for their mighty front claws—responsible for their impressive hunting skills.

A peacock mantis shrimp (Odontodactylus scyllarus) emerges from its hole. These animals use their strong arms to dig burrows along the seabed.

Photograph By GREG LECOEUR , Nat Geo Image Collection

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Hunting and punching

Mantis shrimp are small but impressive predators that can kill prey bigger than themselves. Depending on the species, mantis shrimp use one of two hunting strategies: "Spearer" species lay in wait then skewer unsuspecting fish by using a large spike at the end of their arms. Meanwhile "smashers" like the peacock mantis shrimp use their hammer-like claws to attack their hard-shelled prey—such as crabs and clams—with a powerful punch.

So how does that punch work? When not in use, the shrimp's clubbed arm is fastened securely in place by a latch, allowing energy to build up. A saddle-shaped spring within the arm helps store even more energy. When the latch is released, the spring propels the animal's claw forward in the fraction of a second—50 times faster than we can blink—to hit their prey. At 75 feet per second, it is one of the fastest limb movements of any animal.

The strike is so fast—the speed of a .22 caliber bullet—that it causes bubbles to form and collapse in the water. This energy release creates an impressive force thousands of times the shrimp's bodyweight that combines with the initial strike to smash open the shell of a mantis shrimp's prey, killing the animal inside.

Remarkably, mantis shrimp are unharmed by the blow thanks to complex layers within the club which absorb the impact and prevent the claw from cracking. This innovative design has inspired the development of materials for armor, sports helmets, and vehicles.

Mantis shrimp use the same technique to defend themselves from predators. However, they only use this energy-intensive method of self-defense if they must. When under threat, they perform a behavioral display known as a meral spread before resorting to violence: standing on their hind legs, puffing up their chest, and spreading their arms to look as large and intimidating as possible. If the predator isn't put off by this display, the shrimp will attack.

Mantis Shrimp Packs a PunchPredator in Paradise

Superior vision

These crustaceans have among the most complex eyes in the animal kingdom. Their eyes work both independently and together so they can scan the horizon as well as focus in on prey. Each eye has three focal points, allowing the animal to perceive depth with either eye.

Human eyes have three photoreceptors—cells that detect color—to distinguish between blue, green, and red light. With a staggering 12 photoreceptors, mantis shrimp can see 12 different wavelengths of light. Strangely, however, they are worse at detecting subtle color differences than humans so it's not clear what purpose these photoreceptors serve.

(How mantis shrimp send secret messages using twisted light.)

Unlike humans, mantis shrimp can see UV light and polarized light, which is made up of waves, and are the only animal known to detect circularly polarized light, which travels in a spiral. Researchers suspect this ability could allow them to communicate by displaying patterns on their shells that are visible to other mantis shrimp but not other ocean creatures. This might help them attract a mate or indicate that their burrow is already occupied.

Reproduction

When they're ready to mate, mantis shrimp leave the safety of their burrow and zigzag across the sand until they find a partner. The female will store the male's sperm until she is ready to spawn.

After laying her eggs, the female glues them together with a sticky substance secreted from a cement gland on her abdomen, gathers them up, and carries them into her burrow to look after them until they hatch. The young larvae can deliver the species' famed punch after around nine days.

While not all species are monogamous, zebra mantis shrimp can live together in their burrow for life. But, with the male responsible for all the hunting, the female could starve to death if he is killed while out looking for food, or if he abandons her for a larger female who can produce more eggs.

Threats to survival

Like other reef species, mantis shrimp are likely affected by warming sea temperatures, ocean acidification, habitat destruction, and pollution. They are preyed on by large fish, cuttlefish, squid, and octopus.

Peacock mantis shrimp are popular among aquarium enthusiasts but can be difficult to keep in captivity because they often eat other species and can break glass tanks with their claws.

Although it is possible for humans to eat mantis shrimp—they are considered a delicacy in Asian countries—it's not common because they put up such a fight.

Did you know? If a mantis shrimp loses one of its signature claws, it simply grows another.— Science Inspired by mantis shrimps' eyes, scientists have created digital cameras that use fluorescent imaging to distinguish between cancerous and healthy tissue.— Science Translational Medicine

After molting their shell, mantis shrimp are unable to punch anything for several days.— Journal of Experimental Biology

In 1998, a four-inch mantis shrimp named Tyson smashed through his aquarium tank's quarter-inch-thick glass.— National Geographic

Up to a month after fighting a rival, a mantis shrimp can still remember who won.— National Geographic

Understanding The Mantis Shrimp's Bullet-Like Punch

A peacock mantis shrimp brandishes its hammer-like dactyl clubs.

Michaelgeyer_photography/Shutterstock

With a bullet-like punch that shatters its prey's shell in an instant, it's a wonder that mantis shrimp don't smash themselves to smithereens. Now, scientists have discovered how they protect themselves from damage.

"The mantis shrimp is known for its incredibly powerful strike, which can break mollusk shells and even crack aquarium glass," says Horacio D. Espinosa, a professor at Northwestern University.

These animals have two strong dactyl clubs, which are held back by tendons, storing energy while they're pinned in place. But when the clubs are deployed, the release of stored energy drives them forward, like pinging an elastic band—only much more powerful. Each strike has the force of a .22 caliber bullet. They use this lethal punch to defend their territory or to kill prey in one fell swoop.

Related Reading: What Happens When a Mantis Shrimp Packs a Punch?

"When the mantis shrimp strikes, the impact generates pressure waves onto its target," says Espinosa. "It also creates bubbles, which rapidly collapse to produce shock waves… This secondary shock wave effect, along with the initial impact force, makes the mantis shrimp's strike even more devastating."

Yet, the mantis shrimp itself remains unharmed when it delivers this intense, killer blow. This has intrigued scientists, who wanted to find out how it protects the fragile tissue within its shell from the impact created during its assault.

"To repeatedly execute these high-impact strikes, the mantis shrimp's dactyl club must have a robust protection mechanism to prevent self-damage," Espinosa explains.

Previous studies have explored how the properties of the tough, dactyl club make it crack-resistant, like a strong shield. Although researchers have theorized that mantis shrimp have another layer of defense that filters out sound, "experimental validation on the real mantis shrimp club was missing," he says. To find out more, Espinosa and his team used advanced laser techniques to inspect the shell in minute detail.

Related Reading: Stunning Footage Captures Anglerfish at the Surface

The club is made up of three special layers: a hard coating that protects the surface, a herringbone structure that prevents cracks by dissipating energy and a phononic shield made up of fibers that twist together like a corkscrew. The arrangement of these rotating layers protects the shrimp's delicate body from damaging vibrations by filtering out harmful high-frequency waves. The findings of the study are published in Science.

"Understanding the phononic shielding properties of the mantis shrimp's club has significant implications for both biology and engineering," Espinosa adds. Although further research is needed, learning how the combination of these different factors gives mantis shrimp remarkable bulletproof protection could help inspire new protective materials in the future."

"Biologically, it provides insights into how natural materials evolve to withstand extreme mechanical environments," he says. "From an engineering perspective, these findings could inspire the development of bio-inspired impact-resistant materials with embedded phononic properties for applications in armor, aerospace and advanced protective coatings."

Underwater Heavyweight Mantis Shrimp Also Packs A Natural Energy Shield

The mantis shrimp is a colourful, 10-cm-long resident of the ocean whose appearance belies its reputation as one of the most fearsome predators on the planet.

These unassuming crustaceans use a hammer-shaped appendage called the dactyl club to strike their prey at a blistering 23 m/s (about 50-times faster than the blink of an eye), smashing into the poor creature's body like a bullet from a gun fired point blank. The strike releases enough energy to send small shockwaves through the surrounding water.

But the thing about guns is that every bullet fired has a recoil. It's Newton's third law of motion. If a firearm is not securely braced against the body to absorb it, the sudden backward motion can lead to severe injuries.

Yet despite striking prey hard enough to produce shockwaves, the mantis shrimp remains unharmed. How is this possible?

Lasers reveal a shield

A team of researchers from the US and France found the answer in a specialised microstructure in the mantis shrimp's club. They found that this structure was capable of phononic shielding — a unique ability that allows it to blunt the flow of acoustic waves and thus weaken the recoil the mantis shrimp has.

Their findings were reported in February in Science.

The team fired laser pulses at the microstructure in a rapid sequence that illuminated its response at less than one-billionth of a second at a time. They followed this up with numerical simulations.

"People have looked at the material structure under a microscope but haven't explored the dynamic mechanical behaviour, especially how it responds to wave propagation," Maroun Abi Ghanem, the study's coauthor and a researcher at the Centre National de la Recherche Scientifique, France, said.

"We looked into this behaviour by sending waves through the structure and analysed how they interacted with the material."

Triggering implosions

The dactyl club of a mantis shrimp stores its energy in spring-like elastic structures held together by latch-like tendons. When the latch is released, the club is released. As it moves to deliver its punch, it displaces the surrounding water and forms small low-pressure zones. Inside these zones, the water's density drops so much that it turns into vapour, leaving behind a bubble.

When these bubbles collapse due to the pressure of the surrounding water, they release a considerable amount of heat and shockwaves of very high frequencies, up to hundreds of megahertz.

Thus, each dactyl-club punch delivers two blows: one from its own punch and the other from the collapsing bubbles, and together they are capable of breaking the tough shells of clams, mussels, and other crustaceans.

The dactyl club has a hierarchical design — a fine-tuned blend of mineral and organic materials arranged in three layers. The outermost impact surface is made of a thin but hard inorganic material called hydroxyapatite, which distributes the recoil and prevents it from accumulating at one point. Beneath it, the impact layer and the periodic region contain biopolymer fibres arranged in a pattern that can withstand repeated high-intensity impact without incurring significant damage.

Previous studies have explored the club's material structure and impact resistance. The new study went a step further to check whether the periodic architecture of the materials enhances its mechanical performance.

It does. The team found that the internal arrangement of the microstructure serves as a phononic bandgap: a structure that prevents energy waves of certain frequencies from passing through, or at least significantly attenuated, Horacio Espinosa, a study coauthor and professor of mechanical and biomedical engineering at Northwestern University in Illinois, the US, said.

'An incredible example'

To mimic the ultrafast club strike in the laboratory, the team used a pair of pulsed lasers that emit very short flashes of light: one to generate energy waves on the material surface and the other to detect them.

When the laser was directed onto a material, it absorbed the light and induced thermoelastic expansion, i.E. Heating and expanding the material. This generated a stress wave on the surface, like a miniature earthquake. The team tracked the wave's movement through the shrimp's club to understand energy transfer in the material.

The readings helped researchers draw dispersion diagrams — plots that revealed the bandgaps, or specific frequency ranges, where waves couldn't pass through or were considerably weakened. The appearance of this pattern in the data indicated to the team that the mantis shrimp used phononic shielding to protect itself from the recoil.

"What's even more fascinating is that our findings suggest the club's structure not only resists these intense forces but may also be fine-tuned to control how shock waves propagate through it," Espinosa said. "This dual role of structural robustness and wave manipulation is an incredible example of nature optimising materials at multiple levels."

Here all along

For a long time, scientists believed that materials that could guide the flow of energy in particular ways could only be created in the lab, not in the wild. Such materials are called metamaterials: they have specially tailored geometries to achieve these effects. The new finding about the mantis shrimp stands to change this belief. Nature always had metamaterials.

The study's findings can also be applied to develop synthetic sound-filtering materials for use in protective gear, such as earmuffs for soldiers. They could also inspire new approaches to reducing blast-related injuries in the army and sports, the researchers said in a statement.

"We are working on biomimetic structures inspired by the architecture of the mantis shrimp with a focus on wave trapping," Abi Ghanem said. "We are interested in understanding how the structures trap waves, explore what we can do with this trapped energy, and if it is possible to convert the trapped energy into another form."

Sanjukta Mondal is a chemist-turned-science-writer with experience in writing popular science articles and scripts for STEM YouTube channels.

Published - April 16, 2025 05:30 am IST

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