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How Does the Mantis Shrimp Break Glass Without Hurting Itself?

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Wikimedia Commons

The Harlequin Mantis Shrimp (Odontodactylus scyllarus) typically uses its dactyl clubs to smash shellfish until it gets to the good stuff—soft tissue it can eat. (Check out this video of the clubs in action.) But sometimes, the 7-inch-long shrimp wields its clubs to TKO a tougher foe: aquarium glass. It’s no surprise that it’s possible; this shrimp packs a punch that accelerates to 50mph and delivers almost 160 pounds of instantaneous force. But scientists have long been baffled by how the shrimp can smash glass without doing severe damage to its clubs.

Crustacean Kevlar

The answer lies in the clubs’ structure and composition, which makes them tougher than the strongest synthetic materials. Researchers analyzed the shrimp’s weapons of blunt force destruction using a slew of high-tech tests and found that the outer layer of the club is made of hydroxyapatite, a very hard crystalline calcium-phosphate ceramic material.

On its own, this material would likely fracture on impact. But underneath that hard surface are layers of polysaccharide chitosan, a much more elastic material. Each layer is parallel to the surface, and each is offset from the preceding layer by a slight angle. Because of this structure, cracks would have to continually change direction to propagate, which is what makes damage to the club unlikely. This area also reflects the force of impact back to the creature being struck, further reducing the risk of fracture. (If the shrimp’s club were a car, this region would be its shock absorbers.)

Chitosan fibers at the club’s edges hold it together during these high velocity impacts. The clubs are so tough that scientists are exploring how this type of structure could eventually be used to create better body armor.

Super Vision

Its powerful punch isn’t the only thing extraordinary about the Harlequin Mantis Shrimp. According to a study by the University of Bristol, the creatures, which have the most complex vision system currently known to science, can see 12 colors (humans see only three) and circular polarized light. Scientists plan to use what they’ve learned from its extraordinary vision to improve DVDs.

If you’re thinking about keeping a Mantis shrimp as a pet, do your research: Experts recommend keeping it in an acrylic aquarium separate from your community tank (putting one of these guys in a populated aquarium is like letting Kobayashi loose in a Nathan’s Hot Dog stand). Make sure to include plenty of nooks, crannies and caves that the shrimp can hide in.

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Big Questions
What Is the Difference Between Generic and Name Brand Ibuprofen?
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What is the difference between generic ibuprofen vs. name brands?

Yali Friedman:

I just published a paper that answers this question: Are Generic Drugs Less Safe than their Branded Equivalents?

Here’s the tl;dr version:

Generic drugs are versions of drugs made by companies other than the company which originally developed the drug.

To gain FDA approval, a generic drug must:

  • Contain the same active ingredients as the innovator drug (inactive ingredients may vary)
  • Be identical in strength, dosage form, and route of administration
  • Have the same use indications
  • Be bioequivalent
  • Meet the same batch requirements for identity, strength, purity, and quality
  • Be manufactured under the same strict standards of FDA's good manufacturing practice regulations required for innovator products

I hope you found this answer useful. Feel free to reach out at For more on generic drugs, you can see our resources and whitepapers at Pharmaceutical strategic guidance and whitepapers

This post originally appeared on Quora. Click here to view.

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Big Questions
Do Cats Fart?
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Certain philosophical questions can invade even the most disciplined of minds. Do aliens exist? Can a soul ever be measured? Do cats fart?

While the latter may not have weighed heavily on some of history’s great brains, it’s certainly no less deserving of an answer. And in contrast to existential queries, there’s a pretty definitive response: Yes, they do. We just don’t really hear it.

According to veterinarians who have realized their job sometimes involves answering inane questions about animals passing gas, cats have all the biological hardware necessary for a fart: a gastrointestinal system and an anus. When excess air builds up as a result of gulping breaths or gut bacteria, a pungent cloud will be released from their rear ends. Smell a kitten’s butt sometime and you’ll walk away convinced that cats fart.

The discretion, or lack of audible farts, is probably due to the fact that cats don’t gulp their food like dogs do, leading to less air accumulating in their digestive tract.

So, yes, cats do fart. But they do it with the same grace and stealth they use to approach everything else. Think about that the next time you blame the dog.

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