How A Peacock Shrimp Packs A Punch | June 11, 2012 Issue - Vol. 90 Issue 24 | Chemical & Engineering News
Volume 90 Issue 24 | p. 6 | News of The Week
Issue Date: June 11, 2012 | Web Date: June 7, 2012

How A Peacock Shrimp Packs A Punch

Biomaterials: Layered structure is behind animal’s resilient club
Department: Science & Technology | Collection: Critter Chemistry
News Channels: Biological SCENE, Materials SCENE, Analytical SCENE
Keywords: shrimp, body armor, biomaterials
See the peacock mantis shrimp in shell-bashing action, and listen to UC Riverside undergraduate Stephen Herrera describe the crustacean’s materials science and possible applications.
Credit: Kisailus Lab/Jon Bondy/C&EN

Anybody who has repeatedly punched a wall knows that one’s fist typically suffers as much damage as it inflicts. In contrast, four-inch-long peacock shrimp living in the Pacific and Indian Oceans repeatedly smash through the shells of unsuspecting prey without damaging their own pretty red clubs. That capacity is due to unique layering of stiff and compliant materials in the animal’s club, researchers report in Science (DOI: 10.1126/science.1218764). The club’s chemical makeup could provide a blueprint from which to design resilient materials for body armor and shields.

Less than a quarter-inch long, the shrimp’s club strikes with 200 lb of force, enough to break a glass aquarium, says David Kisailus, a chemical engineer at the University of California, Riverside. “Its club accelerates faster than a .22-caliber bullet, and all this happens underwater,” he adds. “It can also strike thousands of times without breaking.”

The peacock shrimp uses its red clubs to smash the shells of its prey.
Credit: Courtesy of Silke Baron
A photo of a peacock shrimp, a brightly colored crustacean poking out of the sand. On its forelegs are visible two large cream-colored knobs.
The peacock shrimp uses its red clubs to smash the shells of its prey.
Credit: Courtesy of Silke Baron

Kisailus and his colleagues used scanning electron microscopy, X-ray diffraction, micromechanical testing, and computer micromechanical modeling to establish that the club’s strength is a result of the cooperation of three layers of materials.

The impact surface of the club is made up of extremely dense hydroxyapatite. The compressive strength of this region is greater than that of high-temperature engineering ceramics such as zirconium oxide and silicon carbide, Kisailus says. Below the hydroxyapatite is a more compliant layer composed of chitin fibers arranged in helical spirals and surrounded by amorphous mineral. Finally, more chitin wraps around the edges of the club. Unlike the helical chitin fibers in the second layer, these chitin fibers are parallel to each other. The arrangements of both chitin fiber layers, as well as the interface between the hydroxyapatite and chitin regions, prevent major cracks.

“Modern body armor also makes use of a layered structure . . . . However, the ceramic plates [used] fracture on impact and have to be replaced,” says K. Elizabeth Tanner, an engineer at the University of Glasgow, in Scotland, in an associated commentary in Science. Engineers may wish to look to the shrimp’s club to improve the impact resistance of shields over multiple blows, she adds.

Chemical & Engineering News
ISSN 0009-2347
Copyright © American Chemical Society
Joni Garry (June 7, 2012 10:06 PM)
"What do you think? Did the peacock shrimp come about by evolution? Or was it designed?"
George Humphrey (June 8, 2012 5:39 PM)
Hi Joni. How would you test something to determine if it had been designed or 'evolved'?

Simply put, there is no test that you can use to directly determine if a material was designed or evolved. Why is that? Because the structure and ordering of a material gives no indication how it was originated. (unless you already know how that material originated, then you're just matching material)

In past experiments, scientists have created evolutionary systems, where a structure or device goes through huge numbers of evolutionary generations. These experiments were done to see how an evolutionary process would work in a different environment.

In one such experiment, a silicon circuit evolved to the point where it performed it function correctly, but no one, not even the high level scientists who were experts in silicon circuit design, could understand how it worked. The circuit appeared to be totally disconnected from it inputs, and yet performed the work perfectly.

The evolutionary process had discovered and used a property of silicon materials that scientists had never seen before.

btw- the peacock shrimp is the result of evolution, and guess what? Its still evolving, just like we are.
Warrick (May 31, 2013 5:44 PM)
Well played sir George Humphrey, well played, but in a universe with an infinite amount of outcomes, both possibilities could be plausible, even though evolution makes more sense to you, a divine creator makes more sense to him. In the end, life is not about being right or wrong, but making sense.
Albert Holk (June 9, 2012 12:02 PM)
Evolution as there is no evidence of design.
me (June 9, 2012 12:02 PM)
That's easy; evolution. Even if you believe in a creator deity, that deity would have established the existing natural order (nature) that produces evolution in species....
Mike P (June 9, 2012 12:39 PM)
Evolution, of course. Is there an animal CAD program I don't know about?
Harold Ramis (June 9, 2012 1:17 PM)
Evolved. Done.
Gary Jonni (June 9, 2012 1:21 PM)
That's an absurd question. Designed by what/whom, a spirit in the sky? It EVOLVED, doofus.
Not Retarded (June 9, 2012 1:26 PM)
I don't understand the question. Evolution is how all organisms have come into being. Design is a false choice.
Sponge Robert (June 9, 2012 1:42 PM)
what difference would that make?
Ben (June 9, 2012 1:54 PM)
It would seem the peacock shrimp would be a better example of evolution than most animals, since the effectiveness of the clubs are directly related to survival and reproduction, unlike many of the more unusual traits some animals have.
Dr. Dave (June 9, 2012 2:03 PM)
Clearly it was cleverly designed by an omnipotent, oyster-hating deity.
Dr. Phibes (June 9, 2012 2:30 PM)
My buddy designed the shrimp. Stop asking stupid questions.
Jim Hill (June 9, 2012 2:38 PM)
Evolution. There is no designer.
Hed Wigg (June 9, 2012 3:23 PM)
Evolution. As a computational theorist, I can tell you that we use evolutionary algorithms for producing complex solutions all the time, ones that humans would not have come up with. Both natural and artificial selection are excellent tools for solving problems, like how to deliver 500 lbs of force from a shrimp.
glob (June 9, 2012 4:38 PM)
Clearly it was imaginary god(s), this isn't even open to debate.
Dj (June 9, 2012 4:42 PM)
Evolution of course. It the same as the hark, it hasn't changed in 2 00million years because it's already the perfect predator.
Steve (June 9, 2012 6:12 PM)
Evolution, as "was it designed?" has no place in contemporary science discussions. There are religious discussion boards for that.

Next question?
caw mentor (June 9, 2012 6:58 PM)
Sorry I think you'll find most scientists are not going to buy your crazy theory here.

The theory of evolution is not like your theory that you could skate on thin ice, like just some hunch you had one day. Evolution is based on actual real evidence that's been building up, and that we can see all around us.
That doesn't eliminate God or deny his existence, it just doesn't mean that god made this creature like this at the beginning of time. Is there some hand guiding the evolution? maybe, but we have a scientific theory that explains it just fine, and you'll have to look elsewhere for your evidence.
Victor (June 9, 2012 9:20 PM)
Silly Question.
Apostolos von Zedtwitz (June 9, 2012 10:17 PM)
I think the peacock mantis shrimp came about by a self-improving "design." First came some form of shrimp, which eventually found its way into a place where the behaviors and biological structures it now has were necessary, and it evolved over millions of years to have characteristics such as these clubs. (By "it," I mean the general collection of predecessors to the modern peacock shrimp.)
I find it rather amusing to see anyone who thinks such fantastically complicated things such as human brains, peacock mantis shrimp clubs, or even the wing structures of flies, could be "designed" by some being. Perhaps this "being" is really just a representation of the natural flow of things, or the idea of the persistence of life in our universe. After all, our strongest supercomputers only rival the brains of small rodents. Our strongest engineering materials are orders of magnitude weaker than the naturally evolved "clubs" of peacock mantis shrimp. To think that any physical or metaphysical being could even begin design or understand something as complex as the human brain, let alone the entire human body, is somewhat naive. A more realistic and holistic idea is that these things arose out of necessity. After all, why would a peacock "shrimp" need super-strong clubs? If not for the incredible strength of its prey's shells, these clubs never would have evolved. If some supreme being "designed" the peacock shrimp, why not also design its prey to have weaker, more easily cracked shells? Did this supreme being think the shrimp should "work harder" to get dinner? I wouldn't bother making something incomprehensibly strong if I could make it not necessary.
This is a very complicate debate, and I hope it brings forth a fruitful discussion.
Han Solo (June 10, 2012 1:07 AM)
Well, they wouuldnt have a way to hunt without their claws from what I can see. Sooo, most likely designed.
nick (June 10, 2012 1:34 AM)
This isn't the forum for that kind of drivel. Cheers to the researchers and their contributions to science.
Michael Brown (June 10, 2012 4:19 AM)
This site is Chemical and Engineering News, not Woo Central. The idea that there is some undetectable, unknowable, yet omniscient and omnipresent entity out there that refuses to leave any proof for his existence and yet designed everything and loves us all enough to throw us in a lake of fire for all eternity for using our reasoning skills... well, that's a ludicrous proposition that really shows how little Chemical and Engineering knowledge the average person has.
David (June 10, 2012 8:51 AM)
If an omnipotent creator could create so many things a few thousand years ago that are indistinguishable from having evolved over billions of years, why should he blemish his perfect score for creating a world along with its history over something as silly as a crab?

You can bet that if it was created according to design, you would not be able to pinpoint the difference to evolution. God does not do things half-baked, so don't use cheap excuses for not studying his greatness in creating a world consistent with having existed billions of years. If it pleased the Lord to create such a world, it would be heresy to refuse marveling at how all its details make sense.
Skipdallas (June 10, 2012 1:48 PM)
It was designed by evolution over eons to fit in its niche.
AnnaZed (June 10, 2012 2:29 PM)
Evolved, obviously; though that's not an either/or question. ::groan::
David Howland (June 11, 2012 9:48 AM)
Obviously it was designed. That kind of perfection can only be achieved through the hard work of a dedicated, intelligent, and perhaps lucky, designer.

He worked for years and years. He knew his task. The tiny critters he so loved needed a way to capture and eat the armored animals created by the designer's bitter rival. The years passed as he worked. He tried over and over and over again. His first designs were feeble and didn't really work. Most of his creations died off, but some got lucky by striking at young and weak prey. He was persistent. He started to learn the tricks of the materials he had to work with. He kept trying. As new arrangements saw faint promise, he concentrated on improving those designs. After many years he had made some progress but started to despair that he would never complete his task. He began to try wild solutions, just for fun. One day, by dumb luck, he made a multi-layered design just for the artistic beauty. He had used some of his (by now) well known solutions. He found that the little weapons on his beloved creature were the perfect weapon for hunting the prey it needed to live, thrive, and survive. It was finally able to rest, after all those aeons. He decided it was time to get married, so he called up his lawyer to draft a prenuptial agreement...
derp (June 9, 2012 12:37 PM)
It was designed 6000 years ago like everything else. You don't just grow clubs on your hands accidentally, god makes you do it.
Art Carnage (June 9, 2012 1:10 PM)
Since I think it's unlikely any magical sky being was involved, I'll take evolution.
matt (June 9, 2012 1:17 PM)
Joni, isn't that sort of a dumb question? Of course it evolved. We are talking about an actual creature here, not some mythical monster.
GeekJen (June 9, 2012 1:35 PM)
There is no designer in nature. As there is no god.
The end.
Mr. Bear (June 9, 2012 1:43 PM)
Pretty sure it was evolution that brought us this little beastie.
Occam's Razor (June 9, 2012 2:45 PM)
"Another practice that isn't science is embracing ignorance. Yet it's fundamental to the philosophy of intelligent design: I don't know what this is....So it must be the product of a higher intelligence." - Neil Degrasse Tyson
Alessandro Dellavedova (June 9, 2012 3:28 PM)
The Nature is the biggest and most complex laboratory, whose experiments are running since 2 billion years. Well done, little shrimp !
James Rolevink (June 9, 2012 7:31 PM)
If it was 'designed', was it designed by the same designer who also designed the mollusks' protective shells that this little shrimp destroys? Does this mean the designer has a bias against mollusks in favour of shrimps? This could be very interesting to know if ever one was invited to dinner with said designer.
Lee (June 9, 2012 8:48 PM)
Designed. All peacock shrimp are identical. Therefore none have an advantage caused by minor physical variation which would otherwise allow them to spread their genes more than their slightly dis-advantaged contemporaries - ultimately resulting in the standard design being slightly optimized.

Oh wait...
B (June 9, 2012 8:57 PM)
It was designed trough evolutionary process
null (June 10, 2012 5:42 AM)
evolution.. dont be dense
Foobar (June 10, 2012 9:43 AM)
Obvious adaptation. Intelligent design in just a fairy tale.
Deefburger (June 11, 2012 11:38 AM)
Design. Evolution is the designer. No conflict. The design is to evolve. The design question assumes a fixed goal, or a fixed form as the beginning and the end. But this is a false assumption when, if the design IS evolution, then only the basic materials and circumstances are needed as givens, and the goals are ever-changing and so unknown at the outset.

The Design is to Evolve, period.
Kate (June 13, 2012 10:35 PM)
By "evolution" do you mean natural selection? Do you guys mean that peacock shrimps have selected one another on the basis of their clubs over eons? Other shrimps without clubs exist, so it must be possible for shrimps to live without the clubs. Why have these particular shrimps developed these clubs for themselves? Random accident of the particular features of a species has got to be as hard to believe as that there is a God that designed the creature. I say that takes faith. You're entitled to it. Don't assume that it is science to make such assumptions. Prove to me that there is no God.
Wiffle (October 2, 2012 10:24 PM)
1. You clearly misunderstand the process of natural selection. Mantises probably don't choose their mates (some animals do, however I suspect these do not). What happened was that they were more or less forced to mate with shrimps possessing smasher-based raptorial appendages or spearing, depending on the habitat and available resources, because the ones that weren't as well fitted tended to die off more quickly.
2. Mantis shrimps are not true shrimps. Go figure. There are no known species of mantis shrimp without raptorial appendages. They may fall off but they grow back eventually.
3. Mutation? You know that those can be observed and a deity can't right?
4. "Prove to me that there is no God."
Prove to me there wasn't an invisible pink unicorn drinking invisible pineapple juice watching you while you were typing this comment. You can't disprove a flying spaghetti monster either...or a plasmatic bird rib located in the core of a planet 569847895297685976897956576123111045 light years away that cannot be detected by any technology past, present, or future.
You are making the positive claim that a god exists (and a supernatural omnipotent completely beveolent perfect one that sends people to hell and designed imperfect creations at that), thus the burden of proof rests upon you. You must prove it, you can't say "well you can't disprove it" or look at all the crazy crap we'd be believing.

Kindly record atomic absorption spectrum (AAS) to find out % of any metals or its oxides along with chitin moiety. I think it may be due to some metal organic frameworks observed between chitin and metals which makes the shrimp to give more powerful punches without any damage.

Please record HR-TEM equipped with EDAX to find surface morphology information and record X-ray photo electron spectrum to find various metals electronic configuration present in shrimp.

Also record FT-IR, FT-Raman, powder XRD, FE-SEM for further informations.

From the above methodologies one can find out the tough nature of shrimp.

Moreover, exploting this research would make armamaent chemist to build a safe and effective body armour and other biomaterials for furistic application.

These are all my OWN suggestion which I would like to express to top scientists, since giving a spark is more important.
SuperSteve (June 15, 2012 1:32 PM)
Duh.... it evolved, of course. Because if some all-knowing god designed it they would have made it kill with a single center forhead mounted laser beam shooting death antenna. Because that is the best way for any creature to kill its prey and if the god was all-knowing, it would have known that.
Anne (June 15, 2012 3:35 PM)
Just plainly evolution.

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