mega sea creatures, biology, gallery, nudibranch, photography, science, snails

The Savage Colors of Naked, Toxic Sea Snails

There is a kind of soft, toxic snail that lives in the sea called a Nudibranch. The many kinds of Nudibranch all have intense coloration and weird shapes — so weird, in fact, that National Geographic just devoted an entire gallery to the strange creatures. See below for more multicolored, deep-sea weirdness worthy of Cthulhu's spawn.

According to National Geographic:

Nudibranchs crawl through life as slick and naked as a newborn. Snail kin whose ancestors shrugged off the shell millions of years ago, they are just skin, muscle, and organs sliding on trails of slime across ocean floors and coral heads the world over.
Found from sandy shallows and reefs to the murky seabed nearly a mile down, nudibranchs thrive in waters both warm and cold and even around billowing deep-sea vents . . . So why, in habitats swirling with voracious eaters, aren't nudibranchs picked off like shrimp at a barbecue? The 3,000-plus known nudibranch species, it turns out, are well equipped to defend themselves. Not only can they be toughskinned, bumpy, and abrasive, but they've also traded the family shell for less burdensome weaponry: toxic secretions and stinging cells. A few make their own poisons, but most pilfer from the foods they eat. Species that dine on toxic sponges, for example, alter and store the irritating compounds in their bodies and secrete them from skin cells or glands when disturbed. Other nudibranchs hoard capsules of tightly coiled stingers, called nematocysts, ingested from fire corals, anemones, and hydroids. Immune to the sting, the slugs deploy the stolen artillery along their own extremities.

Whoa, hardcore.

But sometimes even the vicious Nudibranchs must find time for love. That's what you're seeing right here, with two Nudibranchs getting busy.

Find out more about these dangerous but recycling-conscious snails, and see over a dozen more pictures in the full gallery at National Geographic.

Living Color: Toxic Nudibranchs [National Geographic] Thanks, Marilyn Terrell!

Photographs by David Doubilet for National Geographic.

7:00 AM on Thu May 15 2008
By Annalee Newitz
30,281 views
41 comments

Comments

CMG at 07:07 AM on 05/15/08
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heh. nudi. sorry, i'm about 12 this morning. those are some cool-looking, toxin-secreting, sea slugs.
tamoko at 07:09 AM on 05/15/08
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These are absolutelt crazy, escpecially the two Nudibranches mating. I love the wierd polop like flower growths on their rumps. Cthulhu would be proud...
tamoko at 07:10 AM on 05/15/08
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@tamoko: polyp
AhnyerKeester at 07:13 AM on 05/15/08
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Awe. Some.
taxbaby at 07:18 AM on 05/15/08
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How cool that you guys picked this up. Nudibranchs are, without a doubt, my favorite invertebrates (with planarians coming in a close second). Love the smiley guy in the last picture.
But just to be clear, they're not ALL poisonous; it depends on what they eat, and they only recycle the toxins of the things they eat. They're also, um, not snails; while people call them 'sea slugs', they're not actually mollusks like snails, slugs or bivalves.
ManchuCandidate at 07:19 AM on 05/15/08
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Very interesting creatures. As much as I like seeing photos like this, I can't help but wonder that there will be morans (sic) who will want them in their aquariums and then later read in the Darwin Awards about some fool who died after being stung by his "pet" glow in the dark toxic slug.
slmcdee at 07:23 AM on 05/15/08
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Snails with racing stripes... who'da thunk it.
taxbaby at 07:26 AM on 05/15/08
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@taxbaby: Scratch that. They're mollusks. I'll just head back to Marine Biology 101, then. Sorry for the bother.
taxbaby at 07:28 AM on 05/15/08
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@ManchuCandidate: No worries; the morans (sic) would have to extensively handle or, um, bite them to be wounded. (Hopefully this is unlikely.)
russdanger at 07:33 AM on 05/15/08
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Imagine how strange and revolting WE must seem to them...
foolish-rain at 07:34 AM on 05/15/08
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This is why I love IO9. Come for the Daily Spoilers, stay for the Sea Slugs! But, uh, based on the fourth pictures, shouldn't this be labeled NSFW?
Log1c at 07:40 AM on 05/15/08
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@slmcdee: Those aren't racing stripes, they are "landing strips" if you know what I mean...
Metropolis at 07:40 AM on 05/15/08
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"....they are just skin, muscle, and organs sliding on trails of slime...."

Ah, aren't we all?

Beautiful photos
strangeasangels at 07:43 AM on 05/15/08
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The second one is adorable, but the last one is SO. FREAKING. CUTE.

She's wearing a little easter bonnet.
foolish-rain at 07:44 AM on 05/15/08
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@ManchuCandidate: When people keep these guys as pets, they almost always end up sucked into a filter and pulped (the slugs, not the idiot aquarists). Of course there are worse fates for bad fish keepers.
Gann at 07:50 AM on 05/15/08
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The smilie guy at then end made me smile :)

These guys would be awesome in an aquarium if all the aforementioned problems were somehow avoidable.
Slatz_Grobnik at 07:51 AM on 05/15/08
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Beautiful, nude, and poisonous; who'd have thought that a sea slug could sum up my typical date?
zenpoet at 07:52 AM on 05/15/08
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@taxbaby: People have a favorite invertibrate? Mine would have to be Platyhelminthes. Why? Sounds like a super-villan name to me, and he is of course one of the most rudimentary creatures in which you can observe Cephelization.

Hows that for 10 year old bio class memories. That, and the fact that there exists a phallic mushroom are really all I remember.

@strangeasangels: it looks like a Nintendo character its so darn cute!
zenpoet at 07:55 AM on 05/15/08
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@strangeasangels: Dear God. If you follow the link and go to the photo gallary, there is one called Thecacera pacifica that actually looks like Pikachu.

Now Nintendo can get sued by Mother Nature and Anascape!
Smeagol92055 at 07:56 AM on 05/15/08
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looks like I picked the wrong week to stop huffing glue.
Git Em SteveDave has a... at 08:00 AM on 05/15/08
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@foolish-rain: So they would have a "Grinding Nemo" themed aquarium?
Stafford at 08:01 AM on 05/15/08
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@Slatz_Grobnik: Thank you to io9's new resident Appalachian style comedian. If I could properly textify a rimshot, I would.
Fwiffo at 08:05 AM on 05/15/08
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The last one looks a '70s pimp!
Calraigh at 08:48 AM on 05/15/08
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Wow.These guys rock.They've better style than the whole red carpet at Cannes put together.
Jeff-Minor at 08:57 AM on 05/15/08
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It kinda makes the creatures from Wormulon look dull and very boring. Seriously, could alien life be any weirder? Planet of the Slugs."
Garrison Dean, King... at 09:07 AM on 05/15/08
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Ah some of God's important work from his formative Sculpey at Summer Camp era.
psdbny at 09:12 AM on 05/15/08
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Even more amazing than their amazing little nudibodies is how the guy photographed them undersea with a little studio set up!
And he was kind enough to let them be cannibalistic before he used them for photos..
SigmundTheSeaMonster at 09:37 AM on 05/15/08
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Neon-Play-doh!
Final at 09:39 AM on 05/15/08
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Slugs going to a Rave
paqman at 09:57 AM on 05/15/08
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Ok, those first ones look like they're made of playdoh.
Pouncer at 10:07 AM on 05/15/08
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Freaky!
Miranda Kali at 10:23 AM on 05/15/08
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They look like cake decorations.
(Hmmm....there's an idea..)
RAHfanboy at 11:00 AM on 05/15/08
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Two nudibranches slime into a nudibar and order a drink. The nudibartender says "That'll be twenty clams. Say, we don't get many nudibranches in here." The one nudibranch looked at the other and then says to the nudibartender, "And at these prices you're not going to!"
Calraigh at 11:16 AM on 05/15/08
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@RAHfanboy:

Laughing my ass off and rolling around on the floor laughing.
Awwww man.
Klebert L. Hall at 11:37 AM on 05/15/08
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Plus, some of them can turn themselves inside out. Talk about a spa treatment...
-Kle.
Eldragon at 11:47 AM on 05/15/08
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The real question is, do these sea snails secrete Adam?
joetato at 11:51 AM on 05/15/08
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@SigmundTheSeaMonster: Good call Sigmund. The same thought occurred to me as well. :-D Now where are the Ultraviolet Legos?
AmishJohn at 04:18 PM on 05/15/08
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For disco colot without the toxins, choose the Mandarin Goby:

[www.fish.com]
Silver_Back at 01:48 PM on 05/16/08
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All together now! Awww!
JimPivonka at 06:08 PM on 05/16/08
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@ taxbaby

bivalves are phylum Mollusca, Class Pelycopoda

Snails and slugs are Mollusca, Gasteropoda

Molluscs also include the Cephalopoda; Octopi, Squid, Nautiloids, extinct Ammonoids. A very cool group.
travelina at 12:19 PM on 05/19/08
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There's a little video that goes along with the photo gallery where David Doubilet talks about these creatures and how he photographed them. There's tango music in the background:
[ngm.nationalgeographic.com]