Weirdos of the Ocean: Stonefish
- Janina Speck
- 3 days ago
- 3 min read
Is it a rock? A cranky lump with fins? Or is it one of the ocean’s most venomous weirdos doing a terrible job of looking friendly?
Meet the stonefish. We see them every now and then on our Nature tours, and they never fail to make someone say, “Wait… that’s a fish?!”
Nature’s Grumpiest Ambush Artist
Stonefish are experts in the ancient art of doing nothing and waiting for food to come to them. They lie around looking like a soggy sponge or rock, perfectly camouflaged on the sea floor, and when something tasty swims past—BAM! They vacuum it up faster than you can say “don’t touch that.”
No chasing. No swimming laps. Just lurking. A truly lazy predator with vibe.
Are They Dangerous?
Yep—but only if you step on one.
Stonefish have venomous spines along their back, and while they’re not out to get you - they are not aggressive!-, standing on one can deliver an extremely bad time (think: searing pain and a rushed trip to hospital).
Guests love the moment when our guide casually points one out and someone goes, “WHERE?!” followed by “OMG THAT’S A FISH?!”
Don’t worry—our guide’s been spotting these guys for years and knows where they like to hang.
Hot tip: wear reef shoes and don’t go poking things that look like rocks but feel… squishy.
Not Just One Ugly Mug
There’s more than one kind of stonefish lurking around our local waters. Here are a few:
Reef Stonefish (Synanceia verrucosa) – Classic big ugly unit. Often covered in algae or sand. You’ve probably paddled past one without realising.
Estuarine Stonefish (Synanceia horrida) – Similar deal but prefers the brackish water near mangroves.
Devil Scorpionfish – Not technically a stonefish, but close enough. Also venomous. Also fond of the “just a rock” look.
We’ve seen orange-ish ones, grey ones, ones that look like rotting coral, and even a very smug-looking green one.
Not All Stonefish Are… Stonefish?
We’ve spotted a few different kinds of these grumpy, lumpy bottom-dwellers on our tours—some with wartier lumps, some with a slight pout. Turns out, Australia’s got at least two true species of stonefish: the Reef Stonefish (Synanceia verrucosa) and the Estuarine Stonefish (Synanceia horrida). But we’ve also likely crossed paths with their equally cranky cousins—like devilfish and scorpionfish. They all share that same A+ camouflage and those nasty venomous spines, so unless you’ve got a marine biologist in your back pocket, it’s sometimes hard to tell who’s who. Either way: don’t step on them.
Stonefish Fun Facts
They can survive out of water for up to 24 hours. Ew.
No swim bladder = they just flop and sink.
Strike speed? 0.015 seconds.
Can live up to 10 years. That’s a lot of lurking.
Their venom is one of the nastiest in the ocean—but they’d prefer you just left them alone.
Safety First
A few things to take away from this post:
LOOK where you walk.
Don't walk barefoot on rocks.
Wear something on your feet in the shallows.
Shuffle your feet rather than stepping.
And don’t touch weird lumps. Or smooth ones.
Who Wore It Better?
Here's me and one of the local stonefish doing our best grumpy face. This big fella was spotted (and safely relocated!). Covered in mud and attitude, he’s a perfect example of just how good their camouflage is—and how easy it is to miss them if you’re not paying attention.
Don't worry—we always keep a safe distance. Except for the selfies, of course.
Ww spot all sorts of Weirdos on our NATURE TOUR! Why not join us for a morning of kayaking, exploring, learning and being amazed!?
