Do you ever have those days when you get home without knowing your roommate is home too, and they sneak up behind you while you are making a sandwich and surprise you so much that you expel your intestinal tract all over them? And you cry: “Damnation Willard! That was the last of my mother’s strawberry jam! I wanted to eat that!”? Am I right? AM I RIGHT!? No? Then you are probably not a sea cucumber.
That’s right folks. Sea cucumbers. Intestines. Expelled. Everywhere. INTESTINES!!! They literally barf their guts out. You might be saying to yourself: “Hey, that sounds like the worst idea ever. Intestines are pretty important (so I’ve heard). Don’t you need them to survive?” Normally you would be right. However, in the case of many sea cucumbers (close relatives of sea urchins, sea stars and other echinoderms), they laugh in the face of your incredulity (and would like you to watch the video of an eviscerating sea cucumber below set to David Powter’s “Bad Day”).
The intentional jettisoning of vital organs, also known as evisceration, is a response to threats to the sea cucumber; such as predatory fish, sea stars, crabs or undergraduate biology students. When feeling harassed and that enough is enough, they cause the attachments holding all their gooey bits inside to soften. Squeezing their body wall, all those formerly attached gooey bits turn them into a living tube of toothpaste. Depending on the species, they can squeeze out their entire intestinal tract, gonads and parts of their respiratory tree. These sticky guts are not only distracting for would-be predators: they are secretly a trap, tangling them up and giving the sea cucumber an opportunity to crawl to freedom! The sea cucumber innards can even contain chemicals toxic to animals who decide to munch on them. Clever, clever cucumbers…
Even cooler than their ability to get rid of their organs in such a spectacular fashion is their ability to grow them back after the fact. That’s right: over the next few weeks sea cucumbers who have eviscerated will grow back all of their vital bits and pieces. Since, not surprisingly, regrowing one’s organs is not a very common occurrence in the animal kingdom, sea cucumbers are very interesting to scientists exploring how organs are formed, or reformed in this case.
These amazing beasties can be found scooting along the bottom of all of the world’s oceans. We pulled up these giant California sea cucumbers on a dredge near Bamfield Marine Sciences Centre in British Columbia.
So go forth and be steeped in love, disgust and appreciation for these weird and wonderful animals. And remember, if you ever find yourself in the presence of a sea cucumber, please, no hugs – maybe just some gentle cuddling, alright?
For more fun information on sea cucumbers and other echinoderms, check out the echinoblog.