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ONETWOTHREE DEATH
April 9, 2013 10:20 PM   Subscribe

Why the Mantis Shrimp is my new favorite animal
posted by flapjax at midnite (78 comments total) 43 users marked this as a favorite

 
This is AWESOME! Thanks! They break aquarium glass? Run Away,,,,!
posted by Katjusa Roquette at 10:32 PM on April 9, 2013


Best Mortal Kombat character ever.
posted by hydrophonic at 10:32 PM on April 9, 2013 [2 favorites]


Not a mantis. Also, not a shrimp.
posted by oulipian at 10:38 PM on April 9, 2013 [14 favorites]


Radiolab's colors episode has a fair bit on these guys, plus (IIRC) a full choir singing their praises.
posted by You Can't Tip a Buick at 10:40 PM on April 9, 2013 [4 favorites]


Jesus Christ! What the hell happened? Did a Claw Shrimp get loose in here?
posted by cthuljew at 10:41 PM on April 9, 2013 [7 favorites]


Not a mantis. Also, not a shrimp.

Talk amongst yourselves.
posted by Greg_Ace at 10:50 PM on April 9, 2013 [21 favorites]


Flagged for lack of mention that the mantis shrimp can see circularly polarized light.
posted by sebastienbailard at 10:52 PM on April 9, 2013 [4 favorites]


I love that we don't have names for the colors it's probably safe to assume butterflies and mantis shrimp can see that we can't.

(The Radiolab color show is mentioned as primary inspiration in the notes at the bottom.)
posted by mediareport at 10:53 PM on April 9, 2013 [1 favorite]


"Not a mantis. Also, not a shrimp."

Boy, wait until I tell you about the water bear.
posted by Eyebrows McGee at 11:01 PM on April 9, 2013 [9 favorites]


No mention how tasty it is?
posted by edd at 11:08 PM on April 9, 2013 [6 favorites]


Those who have tried to find out have never returned.
posted by brundlefly at 11:24 PM on April 9, 2013 [2 favorites]


Also: they're delicious. Delicate little shrimpy lobstery creatures.
posted by gnutron at 11:24 PM on April 9, 2013 [2 favorites]


I'm glad he directly credited the old Radiolab episode at the bottom, I was about to say...
posted by trackofalljades at 11:33 PM on April 9, 2013 [1 favorite]


Well this is awesome.

What it also said to me was that game designers clearly need to study more biology, or more biologists need to get into game design, because even the most fantastical monsters are still boring fluff compared to nature. I mean, a brightly colored death machine with death pummel action? Yes, please.
posted by barnacles at 12:04 AM on April 10, 2013 [2 favorites]


A few weeks ago I was gushing about cuttlefish eyes to a friend, since they can discern polarization of light, and he was like "I'm way more jealous of mantis shrimp. Actually I'm jealous of anyone who can tell red from green"

So yeah, a lot of humans don't even have the three color discernment abilities.
posted by aubilenon at 12:08 AM on April 10, 2013 [1 favorite]


I enjoyed reading every panel of that. Thank you, flapjax, thank you, oatmeal!

Hm, now I'm curious whether other crustaceans also have many more types of cones than we do.
posted by estlin at 12:09 AM on April 10, 2013


Seriously, how can this guy not be excited about seeing circularly polarized light?

For those not in the know (and I'm going to do my best here from memory): light can be linearly polarized and circularly polarized.

Linear light has an amplitude (wave size) that varies in its linear alignment on an x,y plane while travelling along a z axis. Polarized sunglasses work by blocking light that does not conform to a certain range of alignments on the x,y plane, so you get a fairly random amount of scattered light from all objects in you field of view but your not getting ALL the light from those objects and thus things look a bit dimmer.

Circularly polarized light has a fixed amplitude on the x,y plane that moves precessionally in a circular fashion around the z axis (obligatory wiki link). This is crazy cool, as it can interact with molecules/crystals/objects that have a 'handedness' (chiral nature) to them and can have repeatable and measurable effects when interacting with those objects. Not that the object itself changes, though it could, but that the light will be absorbed in certain ways (losing my grasp on the subject here).

The end result of this, for biochemists, is that one can use circularly polarized light to determine how much of a given secondary structure element is present in a protein. Alpha helices, beta sheets, and disordered bits all have different, well known absorption profiles (that unfortunately overlap depending on the sample D:).
posted by Slackermagee at 12:13 AM on April 10, 2013 [8 favorites]


I'm not a terrific fan of The Oatmeal's style, but once you get past the attempted meme engineering this has useful information.

(Disclaimer about the following: I Am Not A Biologist. I'm pretty much blabbing here, because I like describing and explaining things. Maybe some of you find it interesting. Maybe some of you find it bollocks.)

On the subject of color perception:

It's important to remember that colors are, ultimately, an ad hoc kind of thing. There is no absolute standard of perception of color. What we perceive as red is the excitation of certain cells by a particular wavelength of electromagnetic radiation, which is itself only seeable because it's much more evolutionarily advantageous to perceive those wavelengths that are blocked and reflected by matter that those what sail on through solid* objects than those that arrive unhindered from their distant source.

We have cells that detect three colors; that's why we perceive three primary colors of light. Combinations of excited cells produce the shades that lie between. But the relatively low number of primary colors is what makes them special; if we could see more, it is likely that we wouldn't assign as much cultural importance to each one.

(* which really aren't all that solid, of course)

On the Mantis Shrimp's other powers:

When you hear of some animal with a unique ability like this, it is useful to think about it. Think: why don't other animals have this kind of kung fu?

When we hear people talk about evolution, it's often in terms of what precise abilities or features some creature has, like it has a set of class features in some D&D monster manual. But evolution doesn't work like that. To utilize a grossly misleading simplification that leads a little ways in the right direction: it's more likely to leave something "halfway done" than it is to actually evolve some recognizable ability.

Importantly, once some feature has been evolved, it takes continual evolutionary "effort," measured in selected against individuals, to keep it evolved. The same random processes that create the mutations that ultimately produce useful adaptations are even more likely to take them away, or warp them into a non-useful form, and those non-functional versions will overwhelm the working ones unless A. the functional adaptation is sufficiently important to the reproductive survival of the individual, or B. the creature has an instinctual sexual selection bias towards the existence of that feature.

Also, because more ordered structures are easier to damage than less ordered ones, the greater the genetic "weight" necessary to maintain some adaptation, the more likely it can be destroyed by random chance mutations, and thus the less reproductively viable that species will be. And not only that; most adaptations carry other costs to having them as well, with their own evolutionary necessities. Having ultra-fast lightning claws means having a metabolism that can power them, a nervous system that can utilize them, and an exoskeleton that can survive their use.

Thus, the very uniqueness of the Mantis Shrimp's adaptations argues that they are probably an evolutionary dead-end, fascinating for us to observe and study, but not extremely useful to have, at least compared to the less exotic traits possessed by competing species.
posted by JHarris at 12:17 AM on April 10, 2013 [6 favorites]


JHarris: "Thus, the very uniqueness of the Mantis Shrimp's adaptations argues that they are probably an evolutionary dead-end, fascinating for us to observe and study, but not extremely useful to have, at least compared to the less exotic traits possessed by competing species."

While reading the comic (incidentally, has The Oatmeal renounced his previous semi-murky SEO ways? This seemed to be a different angle for him), something along those very lines occurred to me, too. And I wonder what the energy requirements for these pummelarms is, as well as how many times the pummelarms can "fire" before they start to get worn out. Is the length of the mantis shrimp's life determined by how durable its arms are?

Man, we need a mantis shrimp biologist in here.
posted by barnacles at 1:02 AM on April 10, 2013 [2 favorites]


previously
I especially adore this video linked in the comments. Also, yes, they're super tasty.
posted by juv3nal at 1:21 AM on April 10, 2013


Man, we need a mantis shrimp biologist in here.

On the Internet, no one knows you're a manta shrimp
posted by Philosopher Dirtbike at 1:26 AM on April 10, 2013 [4 favorites]


Really fucking tasty as well. In Cantonese they are called "lai liu har" or "pissing prawn" because they squirt water. Fried in their shell they taste amazing. Seafood restaurants keep them in tanks, usually stuffed into plastic bottles (one per bottle) so they don't kill each other.
posted by awfurby at 1:31 AM on April 10, 2013 [3 favorites]


Watching their eyes move is stunning, especially as you track the dark facets oriented towards the camera.

via: http://arthropoda.southernfriedscience.com/?tag=mantis-shrimp
posted by sebastienbailard at 1:44 AM on April 10, 2013 [6 favorites]


The front claws power is incredible and is a sort of a spring or elastically loaded type thing like a sling shot. They can hold them back and leverage huge force into them and release when ready. Ka-pow!

I always think that observing animals in nature corresponds in some ways to the way perception, thought and emotion works in that the processes are made visible in the millions of things in nature.
posted by Skygazer at 1:47 AM on April 10, 2013


These guys were the heroes in a Berserker story I read many years ago. The berserkers in the story were very crab like, and the mantis shrimps stomped hell out of them.

I don't remember the name of the story, but I see at the link that a story titled "Smasher" was reprinted several times.
posted by Bruce H. at 2:13 AM on April 10, 2013 [2 favorites]


There are also some hints of human tetrachromats. No mantis shrimp but maybe a step up from the rest of us in colour perception.
posted by edd at 2:41 AM on April 10, 2013


The fact that this creature is at the same time very tasty, beautiful to look at, conveniently sized for keeping in an aquarium and an aggressive asshole you can eat without remorse is a clear sign that an Intelligent Designer not only exists, but also probably has a financial interest in the Asian seafood business.
posted by Dr Dracator at 2:43 AM on April 10, 2013 [26 favorites]


I'm left wondering how much it would hurt to have one of them attack, say, your hand? I'm guessing it won't take a finger off, but that it would leave you bruised.
posted by Harald74 at 3:42 AM on April 10, 2013


Okay, once again Metafilter has me reaching for eye bleach. That creature is hell to look at - pure nightmare fuel. Half centipede, half cockroach with an LSD palette. SHIVER.

Also, Radiolab is one of the most over-produced and full of itself shows on NPR. It's like listening to a 4-year old who's woken up and devoured every sugar-laced cereal in the kitchen and found your personal recorder lying around somewhere.

I am agitated by this whole experience and must now go lie down and look at puppy books.
posted by Lipstick Thespian at 3:55 AM on April 10, 2013 [9 favorites]


So fantastic! At first I thought to myself "Well this is very interesting and informative" next thing I know I'm actually laughing out loud while still learning a little science and being informed on a rather brilliant little creature! Can we form some sort of curriculum around this ideal? Learning IS fun dammit!
posted by shaunpitz at 4:03 AM on April 10, 2013


How dangerous are the strikes of common mantis shrimps to humans? (Dr. R. Caldwell)

I handle stomatopods every day in our lab and when I'm in the field it is not uncommon to measure and sex 150 animals in an evening. Needless to say, I'm struck fairly often. Some species are far worse than others, but it usually hurts. Even a 2 cm Gonodactylus can draw blood and a 4 cm animal can drive the dactyl tips to the bone. Aside from a two inch slice in my hand made by a large lysiosquillid (by the uropod spine, not the dactyl), the most severe injury I have incurred was from a 7 cm Gonodactylus chiragra that drove its dactyl into the joint of my index finger and the tip broke off. It took some minor surgery to remove it. But that is nothing compared to what happen to a diver from South Africa who wrote me a few years ago describing his attempt to grab by hand an 18 cm Odontodactylus. The animal severely injured his finger which became infected by a chiton-digesting bacteria. The infection did not respond to the usual antibiotics. In the end, they amputated the finger. Be careful out there!

- Dr. Roy Caldwell

via

posted by sebastienbailard at 4:17 AM on April 10, 2013 [8 favorites]


I'm left wondering how much it would hurt to have one of them attack, say, your hand? I'm guessing it won't take a finger off, but that it would leave you bruised.

I would not risk that. They are not called thumb-splitters for no reason.
posted by winna at 4:19 AM on April 10, 2013


There are also some hints of human tetrachromats. No mantis shrimp but maybe a step up from the rest of us in colour perception.

From the Wikipedia article:
One study suggested that 2–3% of the world's women might have the kind of fourth cone that lies between the standard red and green cones, giving, theoretically, a significant increase in color differentiation.[10] Another study suggests that as many as 50% of women and 8% of men may have four photopigments.
WOOT. (/woman who's always been told she's particular with color)
posted by fraula at 4:20 AM on April 10, 2013 [6 favorites]


Mantis shrimp are my favorite marine animal and I feel very lucky to have seen them in the wild a few times. It's not true that all of them are brightly colored, though; O. scyllarus (the peacock/harlequin/clown mantis shrimp) gets the bulk of attention, but many are quite plain and blend in with their surroundings.

I see I've been beaten both to covering the human-injury factor and linking to the long unupdated but still fantastic Lurker's Guide to Stomatopods.
posted by bettafish at 4:21 AM on April 10, 2013


I'm left wondering how much it would hurt to have one of them attack, say, your hand? I'm guessing it won't take a finger off, but that it would leave you bruised.

I've heard that divers call them "thumb splatters".

He's got a few things wrong. The glaring one is the superheated water. That's pistol shrimp, not mantis shrimp. And a pistol shrimp is a true shrimp, while the mantis shrimp is a stomatopod. The pistol shrimp only uses the snapping for territorial display.

Not that I blame the oatmeal for this be off incorrect info; the interwebs just can't help conflating the two.

People most certainly keep them for pets. They can break glass, but since they don't know that fact, it's not a huge risk. Usually when it happens, it's because their prey is too close to the glass.

They are really creepy. If you spot on in a fish store, it will swivel it's eyes back and forth cross your face. I swear they're trying to decide if they can take you.
posted by [insert clever name here] at 4:23 AM on April 10, 2013 [9 favorites]


Be careful out there!

So nature has produced a rapacious, piston-driven killing machine that carries bacteria that will disolve you after the touchy asshole with the short-range point battering ram stabs you?

It's like someone moved the difficulty up a notch. If they move it up again, we will find these things measured in meters rather than centimeters....

Clearly, they are brightly colored so we can keep the heck away from them!
posted by GenjiandProust at 4:23 AM on April 10, 2013 [3 favorites]


I want the gene therapy technology to advance to the point where I can first attain normal color vision and the advance to the levels of color perception available to this shrimp.
posted by humanfont at 4:33 AM on April 10, 2013 [3 favorites]


[insert clever name here]: "He's got a few things wrong. The glaring one is the superheated water. That's pistol shrimp, not mantis shrimp. And a pistol shrimp is a true shrimp, while the mantis shrimp is a stomatopod. The pistol shrimp only uses the snapping for territorial display. "

Actually, both stomatopods and pistol shrimp produce cavitation bubbles which superheat the water (and create light and sound): this TED talk from Dr. Sheila Patek a few years ago talks about the physics of it; you can also check out her lab's website. This video shows the cavitation bubble forming as the mantis shrimp strikes a snail; here's one which measures the force in Newtons of the strike followed by the bubble collapsing.

I'd forgotten about this, but the TED talk addresses the wear-and-tear issue:

"So, one question I often get after this talk -- so I figured I'd answer it now -- is, well, what happens to the animal? Because obviously, if it's breaking snails, the poor limb must be disintegrating. And indeed it does. That's the smashing part of the heel on both these images, and it gets worn away. In fact, I've seen them wear away their heel all the way to the flesh. But one of the convenient things about being an arthropod is that you have to molt. And every three months or so these animals molt, and they build a new limb and it's no problem. Very, very convenient solution to that particular problem."

Also worth noting: some species are monogamous and form life-long pair bonds -- 20 years, in at least one case.
posted by bettafish at 4:46 AM on April 10, 2013 [12 favorites]


Yo dawg, I heard you like power amplification mechanisms that function via pre-stressed components with a catch mechanism, so I put one in an ant.

The trap-jaw ant, less hity more bitey.
posted by andorphin at 5:04 AM on April 10, 2013 [2 favorites]


In Cantonese they are called "lai liu har" or "pissing prawn" because they squirt water.

This explains the otherwise alarming recipe I have for stirfried urinating shrimp.
posted by the duck by the oboe at 5:19 AM on April 10, 2013 [7 favorites]


Metafilter: Getting past the attempted meme engineering
posted by benbenson at 5:22 AM on April 10, 2013 [1 favorite]


This isn't the way that color vision works. It's easy to be reductionist and think that each type of cone in the retina gives us one type of phenomenal color experience. However, subjective color phenomena are not generated at the input level of the retina, but later, in the visual cortex. Once you recognize this, there's really no reason to think that tetrachromats can see colors we don't have names for, or that dichromats are unable to see red and green.

The colorblind have busted input systems, but the same sort of brain that the rest of us do. So they might very well have the same internal color space, but also be more prone to making mistakes when perceiving colors in the world. They recognize the difference between red and green in general, but in particular instances (say, looking at a red towel), they often get it wrong, because their eyes just aren't giving them enough information. This explains why people can go on into adulthood without realizing they and colorblind. If they really couldn't imagine the difference between red and green, this would be difficult to explain. You'd think they'd notice that everyone was talking about color differences that they couldn't comprehend.

Similarly, people or animals with more than three color receptors might have the very same internal color space, but make distinctions in their applications of these colors that the rest of us do not. A wall might look a solid blue to me, whereas to them, one side is sky and the other is aquamarine. It's not like I can't visualize these colors or make sense of them... I just see the wall as one flat color in this one case. So, sorry tetrachromats... your superpowers are a little more mundane than they're usually made out to be.

JHarris: We have cells that detect three colors; that's why we perceive three primary colors of light. Combinations of excited cells produce the shades that lie between. But the relatively low number of primary colors is what makes them special; if we could see more, it is likely that we wouldn't assign as much cultural importance to each one.

The excitation wavelengths for the three types of cone in our eye don't correspond to any interesting primary colors. One is green and another is blue, which some languages don't even have separate words for, and they aren't even subjectively "pure" green and blue. The actual excitation values aren't really that important in our subjective color space, and that's because the processes that generate our subjective color feels happen further downstream from the retina.
posted by painquale at 5:24 AM on April 10, 2013 [11 favorites]


Also worth noting: some species are monogamous and form life-long pair bonds -- 20 years, in at least one case.

Ah, that seems like a dangerous pairing... I can see it now:

"Officer Crowley arrived on scene to find one of the parties severely injured from a concussive force from an alleged domestic dispute. The suspect was last seen fleeing from the scene of the domestic dispute. Suspect is believed to be armed and considered dangerous. Suspect is believed to be a Mantis Shrimp. All officers are advised to approach with caution, and butter sauce."
posted by Nanukthedog at 5:31 AM on April 10, 2013 [5 favorites]


Colorblind people can't imagine how normal humans see color, this thing is so far out there that words fail.
posted by tommasz at 5:52 AM on April 10, 2013


This fish is cray.
posted by Potomac Avenue at 6:10 AM on April 10, 2013 [16 favorites]


(╯°□°)╯︵ 🌈
posted by panaceanot at 6:16 AM on April 10, 2013 [1 favorite]


incidentally, has The Oatmeal renounced his previous semi-murky SEO ways?

Extensively.

posted by psoas at 6:40 AM on April 10, 2013 [8 favorites]


Thus, the very uniqueness of the Mantis Shrimp's adaptations argues that they are probably an evolutionary dead-end

Jesus, don't let them hear you say that. Your last sensations will be a faint smell of brine and a tiny, quiet "WHOOOPAWWW!!!" karate master noise.
posted by Mr. Bad Example at 6:56 AM on April 10, 2013 [7 favorites]


This isn't the way that color vision works. It's easy to be reductionist and think that each type of cone in the retina gives us one type of phenomenal color experience. However, subjective color phenomena are not generated at the input level of the retina, but later, in the visual cortex. Once you recognize this, there's really no reason to think that tetrachromats can see colors we don't have names for, or that dichromats are unable to see red and green.
Plus
We have cells that detect three colors; that's why we perceive three primary colors of light. Combinations of excited cells produce the shades that lie between. But the relatively low number of primary colors is what makes them special; if we could see more, it is likely that we wouldn't assign as much cultural importance to each one.
= +1

Essentially, we can discern three colors so we have three primary colors, we have taste six(-ish) types of taste and we have sweet, salty, sour, spicy, etc., but when you think about the sensation of touch we can discern hundreds of thousands of permeations, and we don't necessarily have great names for them. Sure, there are smooth, rough, flat, sharp, etc, but there's also grooved and spongy and cold and a couple hundred other things we can sense by touch.

So it's not necessarily that there are colors that we can't see*, but instead that the butterflies and killer stomatopods can probably discern dozens if not hundreds of shade variations between two colors that we would have next to each other on a pantone display.

*Of course there are different wavelengths that we can't see, like ultraviolet and infrared, which are probably the technical definition of "color". But it's not necessarily the case that the more cones we have the wider our perception of wavelengths are. However, it is entirely plausible that something that lives in an environment with little to no light would benefit from the evolution of cones that could see those additional spectrum. It's also plausible that the shallow-water creatures can benefit in some other way that we just aren't aware of, similarly to how bees benefit from being able to see the UV light that most flowers reflect.
posted by Blue_Villain at 7:01 AM on April 10, 2013 [2 favorites]


Yet another reason why I prefer swimming in a pool.
posted by xingcat at 7:13 AM on April 10, 2013


Yet another reason why I prefer swimming in a pool

A pool full of mantis shrimp?
posted by sutt at 7:15 AM on April 10, 2013 [1 favorite]


there's really no reason to think that tetrachromats can see colors we don't have names for

Aw, but it's such a great idea. Can I still believe it when no one's looking?
posted by mediareport at 7:17 AM on April 10, 2013 [2 favorites]


This is sheer awesomeness... the animal, the FPP, and the comments.... Thank you!
posted by Debaser626 at 7:18 AM on April 10, 2013


Those of you who are so blithely convinced that having access to new qualia in color perception would be a pretty sweet deal haven't been reading your Lovecraft carefully enough. That this error occurs in the context of a discussion of monsters from the sea makes it even more shameful.
posted by Ipsifendus at 7:24 AM on April 10, 2013 [18 favorites]


What I would like to know is whether biologists have detected any correlation between animals with (assumed) broad color palettes and their evolved coloration. I have no idea, of course, but it does seem like a potentially interesting find if there were a strong correlation.
(The former biology student in me thinks that evolution doesn't work that way, but my background is wildly out of date, and was nascent to begin with.)
posted by staccato signals of constant information at 7:28 AM on April 10, 2013


Those of you who are so blithely convinced that having access to new qualia in color perception would be a pretty sweet deal haven't been reading your Lovecraft carefully enough. That this error occurs in the context of a discussion of monsters from the sea makes it even more shameful.

Aww, I was beaten to The Color Out Of Space by just two posts.
posted by Foosnark at 7:40 AM on April 10, 2013


Jumping on the "more cone types doesn't mean better color perception" bandwagon! With science! A behavioral experiment in which mantis shrimp were trained to punch certain colors of optical fibers established that, indeed, they aren't as good at fine color discrimination as one might intuitively predict based on their variety of cone types. Here's a nice write-up in Science News. MeFi 1, Oatmeal 0.

Alas, I couldn't find a photo or video of the mantis shrimp punching the fibers. Internet, you have failed me.
posted by nicodine at 7:47 AM on April 10, 2013 [5 favorites]


> there's really no reason to think that tetrachromats can see colors we don't have names for

Too true. I can see in the police band and it's pretty drab there, you're not missing much.
posted by jfuller at 7:55 AM on April 10, 2013 [1 favorite]


beautiful? interesting? talented? kill that shit. eat that shit.
posted by SharkParty at 7:56 AM on April 10, 2013 [1 favorite]


I wanted your nick to be "SharkPatty" sooo bad.
posted by lordaych at 8:27 AM on April 10, 2013


They may have more receptors, but they surely have far less visual processing. We're not missing anything in our spectrum that they can see - perhaps they can see deeper into the infra-red or UV than we can, but then there's some variance in human capabilities there. The human cornea filters UV, but people with artificial corneas can see more UV than non-cyborgs - so the night sky and scenes illuminated with appreciable amounts of UV look different to them. (A Nature link from that article goes into some detail of how 'seeing UV' would actually look to those animals that do. Warning: pretty pictures.)

I've long wanted to build a device - in fact, I hope someone has but I've never found it - that lets us change our window into the EM spectrum. It would have a normal colour image display, but sensors that could extend as far as possible up and down the EM spectrum around the visible area. Mapping that much larger window onto our visible spectrum would mean compressing, say, two octaves into one octave and thus reducing our inter-wavelength resolution, but it would sure be fascinating - as it would to slide that window up and down the spectrum.

Incidentally, I've got a visual condition that (among other entertainments) messes with my colour perception. Colours such as yellow and magenta are synthesised in the brain when there are simultaneous spatial responses in the red, green and/or blue fields - so receptors on the same spot of the retina signal that there's energy in their silos, and the brain correlates that with the luminance signal being received from the same spot and guesses that the actual light spectrum isn't 'just' the red or green or whatever but has energy that lies in the overlap. (The receptors are quite broadband, so there is plenty of overlap, but the system works well when the receptors are stimulated by monochromatic light within their receptive frequencies - which is why colour mixing works with lasers.)

However, the mapping from the retina onto the optic nerve bundle (some 1 - 1.5 million nerves), and thence from the optic nerve into the visual cortex, is massively complex and not at all what you might expect. Adjacent receptors do not by any means have to use adjacent neurons, and there are some really interesting bus structures in there... which I do not understand. When you get significant ischemic damage to the optic nerves (that's me, neuro-fans!) then you can end up with quite a lot of weird drop-outs in the visual field, that most certainly means adjacent receptors can produce wildly different outputs. The result - well, the one that's appropriate here - is that the non-primary colours are disrupted. Broad fields of yellow, for example, are covered in graffiti-like squiggles, like someone's gone over them with a white/gray pen, as (I imagine) the interpolation system in the visual cortex tries to deal with some crazy mismatches.

Oh, and it's not at all like "photon hits receptor, receptor fires, signal goes to brain". These babies are firing all the time and modulations in the firing rate are used to perceive - and suppress perception - of things going on Out There in the mysterious phenomenological world which we blithely pretend we know about. At least, that's how I, an interested layman, understand it. More work needed.

Colour perception is weird - and that's before you get into the really weird shit about what it is exactly that's perceiving the output from the visual cortex.
posted by Devonian at 8:56 AM on April 10, 2013 [5 favorites]


One of my favorite creature feature novels, Warren Fahy's Fragment, features an isolated island benefiting from a long line of evolution separate from the rest of Earth. Many of the critters have stomatopod heritage, or are giant stomatopods themselves. The author's site has illustrations of some of them.
posted by kurumi at 9:09 AM on April 10, 2013


Now ya see, that there's why I post that kind of stuff in threads like this. If I'm right I've helped people think about the world, if I'm wrong then I get to adjust my own world model and make it more accurate. Win/win!
posted by JHarris at 9:10 AM on April 10, 2013


... they aren't as good at fine color discrimination as one might intuitively predict based on their variety of cone types.

So you're saying, don't necessarily hire one as your interior decorator?
posted by Greg_Ace at 9:29 AM on April 10, 2013 [1 favorite]


Inman's Law: As an online discussion about The Oatmeal grows longer, the probability of a reference to SEO approaches 1.
posted by monju_bosatsu at 9:40 AM on April 10, 2013


>incidentally, has The Oatmeal renounced his previous semi-murky SEO ways?
Extensively.

That's good to hear. Reading his response makes it sound like it was something he did to survive for a couple of months that, because MEDIA, rapidly became part of the accepted story on the guy and background for everything he's ever done, one report passing the factoid off to the next without asking about its providence like a big game of internet telephone.
posted by JHarris at 9:45 AM on April 10, 2013


Not too long ago [insert clever name here] and I were in the Florida keys, and she pointed to some holes in the shallow water we were standing in and noted that those were mantis shrimp burrows.

I prudently avoided them in much the same way I would avoid the house of a known serial killer who had a particular fetish for people with four letter nicknames.

They are neat, but fuuuuuuuck no. I don't want to be stepping on one of those, thanks.
posted by quin at 10:21 AM on April 10, 2013 [1 favorite]


I wonder if you could cross these with sea monkeys?
posted by PeterMcDermott at 10:30 AM on April 10, 2013


So we'd have extremophile mantis shrimp that could survive nearly anything? No thank you!
posted by [insert clever name here] at 11:07 AM on April 10, 2013


Thus, the very uniqueness of the Mantis Shrimp's adaptations argues that they are probably an evolutionary dead-end, fascinating for us to observe and study, but not extremely useful to have, at least compared to the less exotic traits possessed by competing species.


May not be as unique as we think. "The integration of elastic energy storage and force transmission through specialized joint articulations appears to be a hallmark of arthropod power amplification systems ... trap-jaw ants generate extreme speeds and accelerations during their mandible strikes and have evolved latch systems multiple times using various modifications of joints and mouthparts." Fleas and locusts also appear to utilize similar (and similarly impressive) mechanisms. (pdf source)

Additionally, the basic elements of the power amplification system comprise an engine (muscle), amplifier (spring), and a tool (claw/hammer) and each of these components appear to belong to different developmental modules, possibly allowing for independent evolution of each component. Fascinating stuff.
posted by AceRock at 11:45 AM on April 10, 2013 [1 favorite]


Aww, I was beaten to The Color Out Of Space by just two posts.

The Color Out of Shrimp?
posted by GenjiandProust at 12:41 PM on April 10, 2013


I still wonder if the connection between their additional photoreceptors and their amazing "murder sticks" is related to the color octarine.
posted by Greg_Ace at 1:20 PM on April 10, 2013 [1 favorite]


See also (and the original video).
posted by sebastienbailard at 2:06 PM on April 10, 2013


That creature is hell to look at - pure nightmare fuel. Half centipede, half cockroach with an LSD palette. SHIVER.

Pure nightmare fuel which is very tidy in its personal habits.
posted by sebastienbailard at 2:12 PM on April 10, 2013


Believe it or not, aquarium shops sometimes sell these to unsuspecting newbies buying their first tanks but trust me, you don't want a mantis shrimp, no matter how good they look. I know, I had one. A lot of people end up with them without even knowing it - you buy rock to put in your tank, and there's so many hidey holes that they hitch a ride and before you know it, you've got a lion living in your tank.

I had just installed new rock in my 5 foot saltwater aquarium, and was waiting for the tank to cycle (have the water perameters level out and be safe) before I added livestock, fish, coral etc but the rock came with its own inhabitants, snails, worms, crabs, which was normal. Night after night, I used to hear this annoying knock knock knock from down stairs. It was driving me nuts - and it was loud. I couldn't figure out what it was, I didn't even realise it was coming from the aquarium. All I knew was that it stopped whenever i turned the light on. Meanwhile, in the tank, crabs started to disappear. And snails. I used to see bits of shell. And the knocking continued.

Finally the penny dropped, when pretty much every inhabitant was gone and the tank had almost finished cycling. I had a mantis shrimp. I saw it with a flashlight late at night, it was about 3 inches long. Now until you get can catch it, you pretty much can't progress, because the lion will slaughter whatever it can catch in the tank - they can easily wipe out hundreds of dollars of beautiful marine life in a really brutal fashion. They are hard to catch and they are vicious enough that people have had their thumb split open trying to capture them.

As it was, the water perameters climbed (a completely natural and unavoidable part of the cycle) before settling, and the shrimp died, which is probably the best thing that could have happened, I would never have been able to catch it with 50 kilos of rock to hide in and if I had, I wouldn't have been able to get rid of it, or give it away - would you want a lion?

But I can tell you what, for a few weeks there, I was downright terrified of putting my hand in that tank.
posted by Jubey at 4:32 PM on April 10, 2013 [10 favorites]


Several years back, a couple of those guys got into a big public aquarium. They started seeing bodies every couple of days for weeks, and the mantis shrimp was all over the news of the weird!

And thus, I had to write a song about those guys.
posted by ignignokt at 7:25 PM on April 10, 2013


psoas: "incidentally, has The Oatmeal renounced his previous semi-murky SEO ways?

Extensively.
"


Wow, fascinating stuff, and I had completely missed it. Thanks for sharing that, now I feel a lot better about enjoying his stuff.
posted by barnacles at 8:01 PM on April 10, 2013 [1 favorite]


Anyone notice the 2nd video is titled Die Welt der FANGSCHRECKENKREBSE?

Beware the vicious FANGSCHRECKENKREBSE! He's armed and dangerous.
posted by BlueHorse at 9:03 PM on April 10, 2013 [2 favorites]


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