Australian schoolgirl survives deadly box jellyfish stings Rachael Shardlow, aged 10, survived stings from the world's most poisonous jellyish despite horrific injuries when swimming in Queensland waters. The leg of 10-year-old Australian schoolgirl Rachael Shardlow who survived being stung by a deadly box jellyfish. Photograph: ABC TV/AFP/Getty Images Doctors in Australia have described their amazement at the recovery of a girl who was left unconscious after swimming into the tentacles of a box jellyfish. Rachael Shardlow, 10, suffered horrific injuries to her legs and body when she came into contact with the jellyfish while swimming in an estuary in Queensland, Australia, in December. The girl, who was pulled from the river with the stinging tentacles still clinging to her limbs, lost her vision and then stopped breathing and fell unconscious in the arms of her brother. Jamie Seymour, who has studied jellyfish for 20 years at Queensland's James Cook University told reporters the extent of the sting was "horrific". "When I first saw the pictures of the injuries I just went, 'you know to be honest, this kid should not be alive'. Usually when you see people who have been stung by box jellyfish with that number of the tentacle contacts on their body, it's in a morgue." Box jellyfish are the most dangerous and venomous jellyfish in the world. Adults can grow to 30cm wide with up to 60 tentacles that stretch up to 2 metres long. They are transparent in the water, making them exceptionally difficult to see. At least 63 people are known to have died from being stung by box jellyfish. Each box jellyfish tentacle contains millions of stinging cells called nematocysts, which release venom on contact. Trying to remove the tentacles can cause more venom to be discharged. Death can occur within five minutes of being stung. "These animals kill humans faster than any other venomous animal we know," Dr Seymour said. Australian schoolgirl Rachael Shardlow who survived being stung by a deadly box jellyfish. Photograph: ABC TV/AFP/Getty Images Geoff Shardlow, the girl's father, said his daughter still has scars and some memory loss. "The greatest fear was actual brain damage [but] her cognitive skills and memory tests were all fine," he said. Doctors continue to monitor the girl's recovery. Scientists do not fully understand why box jellyfish are so lethal. The venom usually causes death by causing respiratory or heart failure, though it also contains chemicals that destroy skin cells, causing large and deep patches of scar tissue. The Australian Venom Research Unit at Melbourne University recommends strict supervision of children who are swimming in areas known to be at risk of box jellyfish, as small children are more vulnerable to the jellyfish stings.