Beneath the ocean’s shimmering surface lies a world of silent assassins – fish armed not with teeth or claws, but with venom potent enough to hunt prey or defend against predators.
From coral reefs to sandy seabeds, these seemingly serene creatures hide some of the most effective natural weapons on the planet.
6 venomous fish
Stonefish
Cleverly camouflaged on rock, coral reef or the seabed and capable of staying completely still, stonefish are so dangerous because they are practically invisible. That’s dangerous to the prey they ambush and swallow whole, but equally dangerous to any creature who falls foul of their defensive dorsal spines, which stand on end to deliver a powerful venom if the fish is disturbed.
Stonefish stings are said to be intensely painful and lead to swelling of the entire affected limb within minutes, as well as necrosis and sometimes death, if not treated quickly enough, or depending upon the location of the sting. Fortunately fatalities are rare, with heat immersion (which denatures the venom) and the injection of anti-venom first-line treatments.
Pufferfish
Perhaps one of the world's most famous deadly fish, a notorious creature that packs a serious neurotoxic punch when consumed, is the pufferfish.
Pufferfish are notoriously dangerous to eat because they contain a deadly poison known as tetrodotoxin (TTX), which comes from their food. TTX accumulates in their livers, gonads, skin and intestines (all the parts that skilled Japanese fugu chefs learn to safely chop out).
TTX binds to a victim’s nerve cells, blocking signals and causing paralysis and often death by suffocation - which earns them the pufferfish a very deserved place on our most dangerous sea creatures in the world list, and obviously a place on our deadliest fish list.
Stingray
Your chances of being attacked by a stingray are vanishingly small – these gentle creatures spend their days buried in sand on the seabed and gliding gracefully around the ocean. Yet they have been known to injure people who have accidentally disturbed them, usually by standing on them (though the one that killed Australian conservationist Steve Irwin was swimming).
The danger comes in the form of venomous barbs along their tail, which the stingray whips when threatened. It’s first form of defence, it should be noted, however, is swimming away, which is why divers and snorkellers swimming with stingrays are reminded not to crowd them, and to shuffle their feet on the seabed to warn of their approach.
Lionfish
Capable of striking fear into the heart of divers and snorkellers everywhere, this marine predator is as dangerous as it is beautiful. That’s because in amongst their softly fluttering fins are more than a dozen spines able to deliver a dose of powerful venom that causes extreme pain and, in rare cases, symptoms including temporary paralysis, shortness of breath and nausea.
This beautiful, flamboyant predator has a deadly, venomous streak...
Lionfish, whose range now stretches across the entire Indo-Pacific region, are docile creatures not known to attack humans – injuries occur when people get too close, whether inadvertently or because they are attempting to capture lionfish for the lucrative aquarium trade.
We named them one of the prettiest fish in the ocean
Weever fish
Weever fish are a type of venomous fish that spend most of their lives buried in the sand. To tread on a weever fish is to taunt a tiger: inch-long dorsal spines stab the offender, whose foot soon swells like a red balloon. Dunking the limb in extremely hot water helps break down the toxins, but the swelling can last for days. Distrust of the seaside might linger longer.
Weever fish are the stinging nettles of the sea, primed and armed at all moments for heavy-hitting self-defence. The sting is rarely dangerous, but howls and tears from its victims are testament to its extreme pain.
Scorpionfish
As the name perhaps suggests, scorpionfish have a deadly 'sting' in the form of spines, which are coated in a venomous mucus. While not toxic enough to kill a human, a spine from one of these is still extremely painful.
Scorpionfish tend to live in reefs but can also be found in estuaries, bays and lagoons. Their mottled colour (as well as skin flaps, in some species) means they can blend in well with rocks and reefs. Scorpionfish spend their daylight hours resting and hunt at night.
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