This pooping sea cucumber is one of the weirdest things you’ll ever see


Bec Crew


Bec Crew

Bec Crew is a Sydney-based science communicator with a love for weird and wonderful animals. From strange behaviours and special adaptations to newly discovered species and the researchers who find them, her topics celebrate how alien yet relatable so many of the creatures that live amongst us can be.
By Bec Crew 30 July 2018
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The ocean is home to a colourful array of sea cucumber species, but this has to be the grossest.

Thanks to YouTube, we have access to footage of all kinds of weird and wonderful animals that many of us would have never even heard of 20 years ago. Bizarre trilobite beetles in Southeast Asia. Elusive singing dogs. And this underwater alien creature that has to be seen to be believed.

But just when you’re sure you’ve seen it all, a pooping sea cucumber creeps up on you and simultaneously blows your mind and ruins your morning.

Posted on Twitter by Dr Christopher Mah, a US-based marine biologist specialising in starfish and deep-sea echinoderms, the footage was captured by Japanese diving group, Southern Islander.

So without further ado, let’s just jump in, shall we?

It’s like staring into the void, only to see an impossibly long trail of garbage ejected right back at you.

Sea cucumbers are found all over the world, and are particularly abundant in the Asia Pacific region. They’re found throughout Australia’s coastal waters, including the wonderfully named snot sea cucumber.

Of the 1,250-odd species currently known, many of them look like soft, fat cucumbers, wielding a ring of up to 30 tentacle-like ‘tube feet’ around their mouths, which they use to catch tiny particles of algae, microscopic creatures, or general ocean waste for food.

Considered a good meal for many other marine organisms – and yes, even humans – sea cucumbers are like sitting ducks on the ocean floor, with not all that much up their sleeves to defend themselves with.

But, they are very good at discharging disgusting substances at would-be predators, and some species can do one better – they violently contract their muscles and eject certain internal organs out of their anus as a deterrent, later regenerating anything vital.

Which brings us to the sea cucumber’s butt, which acts as a second mouth, because at this point, of course it does.

Like many species of worms, crustaceans, and other echinoderms, sea cucumbers use the opening of their anus to pump water in and out of their body – some species pump up to 860 millilitres/hour.

As Dr Mah observes, “Sea cucumbers are essentially a big fleshy tube with a mouth and a butt that pumps water through itself.”

The good news is that, while all that sea cucumber poop in the footage above might look like a lot of waste to dump on the ocean floor, it’s actually a really important component of a local ecosystem.

According to Dr Mah, sea cucumber poop buffers against ocean acidification on coral reefs, and provides nutrients for plants such as mangroves and seagrass.

Of course, we can’t talk about sea cucumber anuses without giving the pearlfish a shout-out. Pearlfish have made a name for themselves as notorious squatters of the sea cucumber anus.

As we reported back in 2014, pearlfish tend to live alone inside a sea cucumber, but in one very special case in 1977, scientists found no less than 15 pearlfish living inside a single sea cucumber’s anus.

Here’s more on the bizarre relationship between the sea cucumber and the pearlfish: