19-06-2025
Experts warn summer vacationers of beach seashells so toxic they can 'kill in minutes'
Experts are warning summer vacationers to be on the lookout for a hidden flesh-eating beach threat that could kill them within minutes.
Hiding inside some seashells could be a cone snail — a highly venomous sea snail that can sting people with a poisonous toxin.
People may unknowingly pick up the snail, which is found in coastal rockpools, after being attracted by its stunningly black-and-white patterned shell.
However, if the shell is still inhabited, the snail can harpoon a human with its deadly stinger — injecting a cocktail of toxins that can kill in minutes.
The snails can be found across the southern US coasts, but the types that can inject deadly venom have only been found near San Diego, California, and along Mexico 's Pacific coast.
Larger snails are more likely to deliver deadly stings, scientists say, while children are more at risk of death from stings due to their smaller size.
Some researchers fear the population of the snails, also found in the Indo-Pacific region, is now rising amid warming ocean temperatures.
Tina Petway, an associate curator of molluscs at Houston's Museum of Natural Sciences, Texas, is among the lucky few to survive a sting from the snails.
Petway was alone on a research trip to the Solomon Islands when she picked up a cone snail and, while turning to pick up another, it stung her three times.
She tried to pull the barbs from her skin but, finding she couldn't, she then tried to walk back to her hut — already feeling herself losing vision and consciousness.
Entering the hut moments later, she wrote a short note to her husband about what happened, took a lot of antihistamines - medications used during allergic reactions - and then climbed into bed.
It was three days before she finally woke up again, and realized that she had just survived the deadly snail attack.
'I realized this other hand was on fire,' she said on TikTok, describing the attack, 'so when I looked I could see where it had stung me three times'.
Afterward, she took a two-hour boat ride to the island's airstrip — and then waited there for three days for the next flight to get her off the island.
She says she is routinely plagued by headaches ever since suffering the sting, but has not suffered from any other long-term complications.
Australian marine snail specialist Dr Stephen Smith previously told ABC: 'It's one of the things that I've certainly instilled in my kids, that you don't pick up cone shells.
'Knowing what a cone shell looks like, the habitat you're likely to find them in… It's something we need to get out there so people are aware of the potential risk of this species.'
Cone snails are predators, armed with a deadly harpoon that they use to shoot fish and then inject toxins to immobilize them.
They do not hunt humans, but may deliver a sting if someone picks up their shell or accidentally steps on them in a rockpool or in the ocean.
There are no good estimates on the number of stings and fatalities caused by the snails in the US or among American vacationers every year, although it is thought to be low.
A 2016 study reviewing global data suggested there have been 139 cases of stings reported worldwide, of which 36 were fatal — based on information on cases they could find dating back to the 17th century.
It particularly focused on the conus geographus species — identified by its brown cone-shaped shell with white bands or white spots and known on Mexico's Pacific coast — which it said was behind half of all cases and fatalities.
'Children succumb more often to C. geographus stings than adults and stings by larger snails are lethal more often than stings from smaller snails, regardless of the victim's age,' the researchers said.
Also of concern is the conus textile — identified by a largely white cone-shaped shell covered with brown triangles — which can similarly deliver a nasty cocktail of neurotoxins in its stings.
In many cases, stings from the snails are mild and not dissimilar from one due to a wasp or a bee — causing pain in the area.
In some cases, however, this may progress to cyanosis — or blueness at the site due to decreased blood flow — and even numbness or tingling.
Doctors say that in severe cases, stings can cause numbness in an entire limb that progresses to a loss of sensation around the mouth and then the entire body.
Pictured above is the natural range for conus geographus, the most deadly cone snail
Paralysis can then occur, which also affects the lungs — stopping someone from being able to breath.
There is no antivenom for the stings, but doctors may treat them by immersing the affected area in water that is as hot as is tolerable — with the hot water potentially helping to denature the venom to make it less deadly.
Pressure may also be applied to the affected area, which can help to slow the spread of the poison in the body.
They may also inject a local anesthetic into the wounded area to try to ease the symptoms.
Patients are advised to stay calm and avoid any excessive movement.
