Beneath the ocean's waves are some deadly fish that can strike fear into any human who gets too close. Many a cautionary tale has been told from those who have encountered them, but are these reputations undeserved?
We take a look at the supposedly deadliest fish in the ocean...
10 deadliest fish in the world
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.
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Moray Eel
These fearsome three metre sea serpent-like predators usually target fish, but have been known to bite humans if divers get too close. They also have poor eyesight, which means they could mistake a human arm for a tasty meal.
Amazingly they have a second jaw which launches into the mouth after the first set has snagged its prey, dragging it into the back of its throat.
The moral with this fish - as any wild creature - is to leave them in peace and not try to get too close!
Puffer fish
Perhaps one of the world's most famous deadly fish, a notorious creature that packs a serious neurotoxic punch when consumed, is the pufferfish.
Unlike the equally deadly blue-ringed octopus - one of the deadliest sea creatures - pufferfish are considered a delicacy, appearing on menus in Japan as ‘fugu’.
Chefs wishing to serve the fish must have a special license, issued only to those who’ve undergone training in how to prepare it in such a way that the toxic parts (including the liver, ovaries, eyes and skins) don't contaminate the edible parts.
Before the introduction of the licensing system there were dozens of deaths a year from eating fugu in Japan. Fatalities have since fallen to low single digits - most of the cases of food poisoning that occur these days are as a result of people catching the puffer fish themselves and trying to prepare them at home.
Stingray
Your chances of being attacked by a stingray are vanishingly small – these gentle creatures spend their days buried 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.
Great white shark
The great white shark is perhaps the most famous of all our deadly fish, but does it deserve that fearsome reputation?
Of the 949 confirmed unprovoked attacks by sharks on humans ever recorded, a study looking into which species were implicated shows 351 were by great white sharks, with 59 of these attacks proving fatal.
Tiger and bull sharks are the next deadliest with these three species able to inflict maximum damage because of their large size (great white sharks can measure up to 6m long and weigh 1,800kg), the fact that their teeth have evolved for tearing, not holding prey, and they are commonly found in areas used by humans, such as tropical coastlines.
That said, the team at International Shark Attack Files at the Florida Museum of Natural History stress that these statistics need to be taken with a pinch of salt as easily identifiable species tend to skew any list of shark attacks.
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.
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.
Candiru
This small parasitic fish from the Amazon River can cause significant damage by entering the human urethra, although such incidents are rare and often thought of as myths - however just the thought of it makes us think it deserves a place on this list - along with a place on our weirdest fish list...
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Electric eel
Found in South American waters, electric eels can produce strong electric shocks, which can be deadly to humans, especially in water where the current can cause drowning.
Barracuda
Known for their speed and sharp teeth, barracudas can be aggressive and have been known to attack humans, causing severe injuries - however it is thought that attacks are because it mistakes humans for a fish caught on spear.
However, all though very rare, fatalities from barracuda attacks can happen, with the Florida Museum reporting one in 1947, when a death off Key West was attributed to a barracuda and another case off the coast of North Carolina in 1957.
Piranhas
With razor-sharp teeth and the strongest bite force recorded for any fish, their fearsome reputation is not entirely undeserved.
Some species are quite capable of taking a chunk out of a person or snipping off a finger or toe. The vast majority of attacks, though, involve just a single bite, and they seem to be more likely when swimmers disturb the fish’s nest on the riverbed.
Whether piranhas ever actually kill humans is far from clear. They do form shoals, but this seems to be more about seeking safety in numbers than hunting bigger prey in packs.