The response to Australian box jellyfish envenomation varies from person to person, depending on how well the dermis can clear irritant chitins (the jellyfish exoskeleton) from the skin.Īustralian box jellyfish stings (Darwin Harbour) It can be followed by whip-like hypopigmentation or hyperpigmentation. Full-thickness skin necrosis can occur 1–2 weeks later.Blisters may form within minutes of contact. Linear welts are a brownish-purple colour and up to 10 mm in width.Exquisite pain, itch and welts at the area of contact.Skin symptoms occur immediately upon contact and include: The seriousness of the sting relates to the size of the box jellyfish (those with a bell over 150 mm are considered highly dangerous). Most Australian box jellyfish stings are a nuisance rather than a medical threat. It has direct effects on muscle and nerves, and can cause chronic immunological complications. TheAustralian box jellyfish toxin is injected into the skin. What are the local signs of Australian box jellyfish envenomation? These travel 67 km/hour with an impact pressure on the epidermis of 7.7 GPa (about 1,116,790.5 psi).Įach poison-filled dart is filled with porins (transmembrane proteins), neurotoxic peptides and bioactive lipids. Within 700 Ns of contact, the nematocyst capsules fire thousands of barbed, poison-filled darts. The venom is spread by tiny nematocysts, each containing picograms (trillionths of a gram) of proteins.Įnvenomation (or stinging) occurs when human skin contacts the thousands of densely packed nematocysts that line the jellyfish tentacles.The toxin proteins are fragile and easily degraded by unfavourable temperatures and pH.It is difficult to collect pure venom without contamination - until recently, the most widely used method of toxin extraction involved pulverising the tentacles and nematocysts (or ‘stinging cells’).Stings from the Australian box jellyfish are difficult to study because: What is the mechanism and toxicology of Australian box jellyfish stings? Rain and strong winds, but not cloudy weather, are a deterrent to the jellyfish.Stings most often occur in people entering the water between 3 and 6 pm, with an outbound tide.About 37% of Australian box jellyfish stings occur in children.Stings most commonly occur in adult men in water less than 100 mm deep.Box jellyfish are most commonly present in tropical Australian waters from November to April each year, with 8% of stings occurring outside this period.Who is affected by Australian box jellyfish stings? However, an opportunistic deep-sea video study in North-western Australia found large numbers at depths of 39–56 m (64 in a 1500 m tow or 0.05 m −2). Until recently, it was thought that Australian box jellyfish were rare in deep waters as marine surveys of the Great Barrier Reef found few away from the shore or deeper than 5 m. Their northern-most reach has yet to be found, and their overall biogeography is uncertain. The Australian box jellyfish is found in coastal waters from northern Australia but its distribution can now be widened to include nearby areas of the Indo-West-Pacific Ocean. Their stings injure the skin and can cause severe systemic effects. The box jellyfish is difficult for victims to see, and harder to avoid, with their near-transparent tentacles extending up to 300 mm. The Australian box jellyfish, has been responsible for over 70 fatal stings or ‘envenomings’ since 1883. Cubozoans also include several species of four tentacled box jellyfish that cause Irukandji syndrome.Īustralian box jellyfish specimens have weighed up to 6 kg they are composed of a large umbrella-like bell with four bundles of tentacles arising from the corners of the bell. Of the 10,000 known species of Cnidaria, about 100 are potentially dangerous to humans.
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