Beautiful, Terrifying Mantis Shrimp

Thank you to @dorographie on Unsplash for being brave enough to get close to this beautiful terror and take a picture

As if praying mantises weren’t deadly enough (stay tuned), apparently they’ve got a cousin in the ocean who likes to punch through oyster shells for fun.

Think about that for a second. I can’t punch through an oyster shell. You probably can’t punch through an oyster shell. But this tiny, rainbow-colored shrimp is just pulverizing mollusks with its rainbow-colored fists left and right (even shell-less mollusks that get too close: check out this video of a mantis shrimp beating up an octopus).

The power behind a mantis shrimp punch comes from its speed, clocking in at 10 meters per second or about 50mph. These speedy jabs allow the mantis shrimp to not only obliterate the shells of its crustacean and mollusk prey, but also to crack through thick glass – no aquarium time for these angry arthropods. A punch that fast also produces heat, which creates cavitation bubbles where the water instantly evaporates and implodes like a tiny backwards firework, causing even more damage to the mantis shrimp’s target.

…Yeah, maybe it’s best to just leave some animals alone in the ocean. I don’t think anyone wants to go to an aquarium and get chased around by a growling firework shrimp that wants to punch them with the same bullet-fists it used to bust out of its enclosure. And yes, I said growling.

Not all mantis shrimp use their forelimbs for smashing things, though: some like to impale their prey instead. These crustaceans will lie in wait under the sand or in a concealed crevice until their prey wanders by before leaping out and stabbing an arm through them. Lovely.

Like most arthropods discussed in The ArthroBlogger, “mantis shrimp” don’t have a very taxonomically accurate name. While their fast forelimbs are akin to those of a praying mantis, mantis shrimp are not insects. Additionally, they’re members of the crustacean order Stomatopoda while shrimp belong to the order Decapoda. For accuracy’s sake, I suggest we rename them the “pulverizing rainbows of the sea,” or maybe “stabby-punchy rainbows of the sea” to include the ones that prefer stabbing over smacking.

There over five hundred species of mantis shrimp. Whether they’re the size of inchworms or big enough to fill a footlong hotdog bun, every single one is either a stealthy-stabber or a firework-puncher, so it’s probably best to admire them from a distance. In fact, every mantis shrimp is basically just colorful, chaotic hodgepodge of superpowers: they breathe underwater (duh), they can hit things really fast (noted), they make water implode (apparently), and just for kicks, they can see many, many more colors than we can (yep… wait what?).

Have you ever looked at your dog and gone, “aw, it’s so sad that you can’t see green. You’ll never know what grass really looks like”? Somewhere, somehow, a mantis shrimp is watching you and saying, “man, it’s a shame they can’t see bolgo. Or tyorp. Or flarm. So sad.” Obviously, I just made those colors up, but whereas humans only have three kinds of photoreceptors in our eyes that allow us to see red, green, and blue light, mantis shrimp have twelve. By my judgement, this implies that mantis shrimp can see at least four times as many colors as we can (don’t quote me on that, it’s been a hot minute since I studied eyeball physiology). However, scientists have deduced that all that color may be a bit overwhelming for our bullet-fisted friends, as they have more trouble differentiating between different shades of the same color than we do. Still, even though mantis shrimp look pretty colorful to us already, I bet they see each other in a much more extravagant light than we can imagine.

Yeah, I think I’d trade my ability to differentiate between shades of blue to see whatever the combination of bolgo and flarm is any day.

With their magical eyeballs in mind, it’s nice to know there’s more to mantis shrimp than just punching and stabbing. In fact, the stabby-punchy rainbows of the sea are actually pretty romantic, too: they mate for life and spend their days hunting with their mates, raising offspring together, and snuggling together in their sandy burrows watching the ocean world float by in all its unimaginably colorful splendor. Mantis shrimp aren’t just clam-bullies either, but actually help keep various benthic populations under control. They also act as figurative canaries in the figurative ocean coal mine, as their sensitivity to pollution makes them good indicators of the health of their habitat.

Speaking of habitat, there’s a chance this post has made you a little nervous about running into a bullet-fisted firework puncher at the beach, but fear not: mantis shrimp typically live in reefs or near shore in the warm, shallow waters of the Indian and Pacific Oceans, so if you’re on the Atlantic coast like me, you’re safe. I mean, relatively speaking. We’ve still got sharks and jellyfish and riptides, but at least you won’t get smacked by a living rainbow.

If you live on the warmer end of one of the other coastlines, though, well… keep an ear out for the sound of a quarter smacking cement at 50mph (behold my super accurate description of a mantis shrimp punching a clam) and just try to keep your distance. If that thing can bust a crab open with just a few hits, imagine what it could do to your shinbone. Yeesh.

One Comment on “Beautiful, Terrifying Mantis Shrimp

  1. Pingback: Powerful Pistol Shrimp – The ArthroBlogger

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