Cone snails

With the venom of some cone snail species (also known as cone shells) containing the most potent neurotoxins known to man these sea creatures may look harmless, but a sting from one can be lethal. Don’t believe us? Then read on to find out how these pretty-looking shells could possibly pose a threat. 

What is a cone snail?

There are between 500 – 600 cone snail species worldwide, of which 133 are believed to live in the waters of the Great Barrier Reef in Queensland. Housed in a brightly patterned or coloured shell, they have been described as an underwater tank by National Geographic, slowly scouring for prey armed with a deadly weapon. They can prey on fish, molluscs, or worms with the most venomous being those that feed on fish and molluscs and which are also responsible for serious injuries to humans.  

How does it hunt its prey?

The four tubes protruding from the front of the cone includes its two eye stalks; a siphon, used to inhale water and detect prey; and the proboscis, a long and mobile appendage containing a lethal harpoon loaded with at least 100 different neurotoxins; and the radula, a row of tiny teeth arranged in a ribbon. Cones typically hunt at night, luring their victim in with their proboscis, before stabbing them with a paralysing toxin. The cone snail will then engulf their prey.    

Have there been any fatalities from a cone snail?

The geography cone (Conus geographus) is a large species of cone snail, reaching up to 120mm long, is thought to be responsible for the death of a young man at Hayman Island on the Great Barrier Reef in 1935 in the Whitsundays. This is the only death that has been recorded from a cone snail in Australia. And while they are lethal, the cone snail is not aggressive to humans, with stings usually occurring when divers handle them in deep reef waters. 

Where do they live?

The cone snail is entirely marine, and can be found under stones, sand, rubble, or even among weed depending on the species’ preference. Along the Australian coastline, they can be found from north Western Australia to southern Queensland but they are widely distributed throughout the Indian and Pacific oceans, the Caribbean and Red seas. It is unlikely swimmers or snorkellers will find them in shallow waters.

What if I see one?

Do not pick it up, under any circumstances. It’s also important to also be aware that a cone shell on a beach may still have a living animal inside so it is best to leave it alone.  

What are the symptoms of a sting?

Stings usually occur in the hands because of handling and have been likened to a bee or wasp sting but the symptoms can then become quite severe, with intense pain, numbness or tingling in the area. In severe cases, victims may have difficulty speaking, experience double vision, fainting, and even respiratory paralysis. 

How do you treat a sting?

  • Seek medical attention immediately by calling 000.
  • While there is no antivenom available there are measures that can be put in place to relieve the pain.
    • First, immerse the affected area in water as hot as is tolerable.
    • Use the pressure immobilisation technique with an elastic bandage to wrap the limb of the sting. While you’ll need to bind the limb firmly, do not block circulation – fingers and toes should remain pink.
    • Try to stay as calm and still as possible while waiting for medical attention.
    • In extreme cases, CPR may be necessary. 
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