'Prickly bastard': The fish you won't see before it stings
A warning about the bullrout, or freshwater stonefish, seems to have hit a nerve with people on the Northern Rivers.
Plenty of people have encountered this spiky creature, and there are some horror stories to tell.
These fish can grow to 30cm in length, but the bullrout is usually spotted between 5cm and 10cm.
Don't let their size fool you.
The spines on these tiny fish can leave you in immense pain for days.
Claire Wotton said they used to be in the river at Casino and caused "murderous pain".
Peter Clarke-Williams got stung by one on Tuesday.
"Absolutely the worst pain I have ever been in," he wrote on The Northern Star's Facebook page.
"Within 20 minutes of getting pricked in the hand, my whole arm was in excruciating pain like I have never felt before.
"The little prick (see what I did there?) got himself stuck in my crab pot and he stuck me when I was trying to release him."
Maddie Andrews wrote: "I have stepped on one of those prickly bastards at Tosha Falls in Alstonville.
"The pain was horrendous and scared me from swimming at waterholes now.
"I got out to check my foot and couldn't see a mark but then the burning pain and swelling started … my foot still ached for a week after."
John Keating saved a bullrout after a fish kill near the Casino boat ramp, and put it in his fish tank.
"They are very pretty freshwater fish, but give an extremely painfully bite and sting," he wrote.
"Near impossible to see in the river until you have stood on it."
Ross Prior said there were "heaps" of bullrout in the creeks around Eltham and Bexhill when he was growing up, while Carolyn Fisher said there were plenty at the weir in Casino when she was a kid in the 1970s.
Peter Klaus: "I got tagged by one fishing behind the old co-op in Ballina years ago. An old fisherman grabbed an onion out of the veggie garden and rubbed it on the spot. Eased it in about five minutes."
Natalie Stiles: "My son caught one in the Wilsons River near Lismore recently."
Kirk Von Rostock: "I got stung badly when I was 12. I grabbed one not knowing what it was. Spines went about 1cm into my hand. Agony."
And for all those now planning to abandon their freshwater swimming spots and head to the nearest beach instead, Ross Bienke said: "I've even caught them in saltwater."