The sea cucumber is the broad category for about 1,200 echinoderm species within class Holothuroidea. Most inhabit the benthic zone of the world’s oceans, scavenging detritus from the sea floor and eating tiny algae particles. Like all members of phylum Echinodermata, sea cucumbers have an endoskeleton just below the skin. Oh – and when threatened, many a sea cucumber will shoot its organs out of its anus. In shallow water, they can form dense populations and comprise most of an ecosystem’s biomass. They sometimes send their own innards shooting out their anuses. The top skin covers microscopic pieces of skeleton called spicules. Just to make sure you got this, they defend themselves by defecating their own internal organs. And how they came up with this strategy is anyone’s guess.
It’s all you, dude.
Choosing to defecate its own organs as a defense technique is surprising and would appear, prima facie, to be much less useful than, say, actually doing something. Apparently the goal is to make a predator, no matter how famished, sick to its stomach and lose its appetite. Failing that, shooting its very own guts out of its very own anus is just so pathetic that even the hardest of predatory fish will give it an awkward pat on the back before making up an excuse to just get the hell out of there.
I’m gonna go.
Interestingly, the blood of sea cucumbers is yellow in color because as much as ten percent of its blood cell pigment is vanadium.* This was discovered when a scientist startled a sea cucumber and got an unexpected view of its entire insides.
The sea cucumber can also reproduce both sexually and asexually. However, given that its one and only trick is defecating its innards, we’re guessing it’s mostly asexual.
As with all disgusting ocean creatures, the sea cucumber is considered a delicacy in Asia. And if you happen to get one that just shot its guts out its anus – well, you can imagine the excitement.
Oh it’s disgusting and horrible? I’ll take three.
Basically, the sea cucumber digs around looking for dirt to eat, and when something bothers it, it shoots its guts out. It’s like if you spent your life lying in the grass at a park looking for leftover chips to eat, and when the cops came to ask you what you were doing you promptly started kicking yourself in the crotch and vomiting up kidneys. Actually, that would probably work pretty well. But good luck finding work after that.
GRADE: D
*Vanabins are a group of proteins that bind the metal vanadium; the few organisms that have vanabins in their blood are able to bind vanadium at levels 100 times that of seawater. Currently it is a mystery as to exactly why sea cucumbers and other organisms collect vanadium. Another mystery is why sea cucumbers shoot their organs from their anuses.
Animal Review 
This site is perhaps the happiest accident I’ve run across. Love your sense of humor…keep up the hilarious work!
I think this entry tops even the King Cobra one… and I can’t believe I just said that. No wait, what? I love King Cobras.
Haha, the captions are fantastic. “I’m just gonna gooooo…”
I just spewed my colon
Oh man … way to capture the essence of the sea cucumber. I too wonder how they have come up with such a unique way of “defending” themselves? I think for humans … projectile puke would be a very appropriate form similar to the sea cucumber.
we eat these in china
Question: do they die after they shoot their guts out, or can they somehow pull their guts back in? i know that sounds like a really dumb question…i just figure they end up like bees where bees sting people and then die. p.s. they sorta taste like nothing+soil.
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Surly Suzie,
No they do not die they use that defense to entangle and distract the predator while it makes it’s escape. If there is no predator to eat the internal organs it does retract them. If they are eaten the organ will grow back again in 1 to 5 weeks not harming the Sea cucumber.
One should also perhaps mention Holothurin, the incredibly strong saponin toxin they produce when ejecting their innards. Saponin agents being basically like detergents, good at reducing surface tension in water, and breaking apart lipids.
Cellular membranes in animals are composed of lipids. Guess what happens to a fish that gets a gills-full dose of holothurin from the sea cucumber it just annoyed. The nice way is to say that no more gas diffusion across membranes is occurring in its breathing bits.
Salt-Water aquaria enthusiasts tend to look warily on sea-cucumbers in their systems, as unlike an ocean, there is little dilution factor going on. Many an aquarium and its residents have been laid to waste by what is termed a ‘Cuke Nuke’.
In the self-evisceration state, the cucumber hunkers down and exposes a keratinous integument to its own toxic fallout for awhile until the current dillutes things enough that it is fine to move on and begin organ regeneration.
In an aquaria suffused with holothurin, there is no dillution and the cucumber eventually dies as well. In a sea cucumber nuclear war, the only winning move is not to play.
Awesome post, but you missed two fabulous factoids about sea cucumbers’ butts: They breathe out of their butts AND some animals hide in sea cucumbers’ butts. http://maukamakai.wordpress.com/2009/09/03/cool-critter-sea-cucumber/
Yep, in my culture people eat this stuff too. Not only are they eaten, they are also made into cosmetic products and medicinal oils. I’ve seen how the cucumbers are dried and then cut up and made into deee-licious stews.
For the record, in my undergraduate years studying Biology, we had one of these specimens in the lab… looked like a foul, flaccid penis to me. So unlike my countrymen, I WILL NOT be consuming sea cucumbers anytime soon. If ever. Ewww.
Well. it’s not a mistery!!! They spell their got as a defense to predators and bad enviromental conditions! They continue living without their organs with low level of metabolism. And they don’t have vanadium! Tunicata does.