Weirdos of the Ocean: Sea Cucumbers
- Janina Speck
- Jul 17
- 3 min read
Updated: Aug 1
If there’s one ocean creature guaranteed to get a reaction on our Nature Tour, it’s the humble sea cucumber.
Usually something along the lines of: “Wait… is that thing alive?” or “It looks like a slug… but squishier…”
And sometimes? You get the full Liquid Adventures experience, like one recent guest did:
“One minute we’re gliding peacefully past mangroves, the next she’s yelling, ‘LOOK AT THIS ABSURD CREATURE!’ and thrusting a sea cucumber at us with glee.”
Guilty. But honestly — how can you not get excited about these weird little bottom-dwellers?
What even is a sea cucumber?
Despite the name, sea cucumbers aren’t veggies. They’re animals — and believe it or not, they’re closely related to sea stars and sea urchins. All part of the Echinoderm family (that’s ocean-speak for “spiny-skinned weirdos”).
They’ve got soft, sausage-shaped bodies, leathery skin, and hundreds of little tube feet to help them crawl along the sand. Well… most of them do. More on that in a sec.
Nature’s clean-up crew
Sea cucumbers might look odd, but they do an important job — they’re the vacuum cleaners of the ocean.
They suck up sand, digest tiny bits of organic matter and algae, and “clean” the seafloor as they go. Their sandy poop actually helps recycle nutrients back into the ecosystem — good news for the reef.
The weirdest ones we’ve ever seen...
After 14 years of tours in this estuary, we thought we’d seen it all when it comes to sea cucumbers. Until recently. Out of nowhere, dozens of long, squiggly, alien-looking sea cucumbers called Opheodesoma turned up — smack bang in broad daylight.
These aren’t your average bumpy, sausage-shaped sea cucumbers. Nope. These guys looked more like sea noodles than sea pickles.
How are they different?
🥒 No tube feet — they move more like worms
🥒 Long and flexible — some were over a metre!
🥒 Covered in microscopic anchor-shaped spines
🥒 Strictly nocturnal… usually
So why did they suddenly crash the party during the day?
It was just two days before the new moon — prime time for sea cucumber spawning season. When the tide’s right and the moon says go, they throw caution (and a whole lot of eggs and sperm) to the current — and come out in the open for a rare daytime appearance.
Nature never gets boring out here.
The elusive Golden Sandfish
Another rare one we spotted — a Golden Sandfish, right here in the estuary.
Golden Sandfish are one of the most prized and unusual sea cucumbers in the Indo-Pacific — not just for their looks, but because they’re edible (don’t worry, ours are safe). Their sandy-golden colour and plump body make them stand out from your average sea cucumber… if you’re lucky enough to spot one.
It was a treat to tick that off the list!
Weird but true sea cucumber facts:
✔ Some can literally vomit their guts as a defence (don’t worry, they grow them back)
✔ They breathe through their bottoms — yep, oxygen gets absorbed through their… well, rear end
✔ There are over 1,200 species worldwide — from tiny ones to giants over 2 metres long
✔ They’ve been around for over 400 million years — outlasting the dinosaurs.
A pickle of sea cucumbers
What’s the collective noun for these wobbly oddballs? Fittingly, it’s called a pickle of sea cucumbers. Makes sense — they already look halfway to being brined and jarred.
Spotted on tour
We see sea cucumbers regularly on our Nature Tour. And with rare sightings like the Golden Sandfish and the squiggly sea noodle invasion, there’s always a new weirdo to meet.
They might not swim, sting, or chase anything — but if you slow down and have a proper look, they’re a perfect reminder that the ocean is full of weirdos quietly doing their thing… and making the whole system work.
Want to meet the weirdos for yourself? Book a Nature Tour and come exploring with us — you never know what you’ll spot!
